Name: preparation of single-cohort colonies and hormone treatment of worker honeybees to analyze physiology associated with role and/or endocrine system
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Description: Watch this Scientific Journal Video about Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System at JoVE.com

This work was supported by a Grant-in-Aid for Scientific Research (B) and a Grant-in Aid for Scientific Research on Innovative Areas 'Systems Molecular Ethology' from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. T.U. was the recipient of a Grant-Aid from the Japan Society for the Promotion of Science for Young Scientists.

1. Preparation of Single-cohort Colonies
<ol>
	<li>Prepare three honeybee colonies to create two single-cohort colonies and to obtain a sufficient number of newly emerged workers.
	<ol>
		<li>Check that some pupae in the capped peripheral cells in the combs have brown eyes and a pigmented cuticle by opening the capped combs using tweezers. If these pupae exist in peripheral comb cells, most of pupae in the whole combs will emerge in approximately 1-3 days.</li>
		<li>Subsequently, collect the combs containing these pup...

<ol>
	<li>Wilson, E. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The insect societies. , (1971).</li><li>Winston, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The biology of the honey bee. , (1987).</li><li>Lindauer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ein+Beitrag+zur+Frage+der+Arbeitsteilung+im+Bienenstaat.">Ein Beitrag zur Frage der Arbeitsteilung im Bienenstaat.</a> Zeitschrift f&#252;r vergleichende Physiologie. 34 (4), 299-345 (1952).</li><li>Sakagami, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Untersuchungen+uber+die+Arbeitsteilung+in+einen+Zwergvolk+der+Honigbienen.+Beitrage+zur+Biologie+des+Bienenvolkes,+Apis+mellifera+L.">Untersuchungen uber die Arbeitsteilung in einen Zwergvolk der Honigbienen. Beitrage zur Biologie des Bienenvolkes, Apis mellifera L.</a> I. Jap J Zool. 11, 117-185 (1953).</li><li>Kubo, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Change+in+the+expression+of+hypopharyngeal-gland+proteins+of+the+worker+honeybees+(Apis+mellifera+L.)+with+age+and/or+role.">Change in the expression of hypopharyngeal-gland proteins of the worker honeybees (Apis mellifera L.) with age and/or role.</a> J Biochem. 119 (2), 291-295 (1996).</li><li>Ohashi, K., Natori, S., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Change+in+the+mode+of+gene+expression+of+the+hypopharyngeal+gland+cells+with+an+age-dependent+role+change+of+the+worker+honeybee+Apis+mellifera+L.">Change in the mode of gene expression of the hypopharyngeal gland cells with an age-dependent role change of the worker honeybee Apis mellifera L.</a> Eur J Biochem. 249 (3), 797-802 (1997).</li><li>Ohashi, K., Natori, S., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+amylase+and+glucose+oxidase+in+the+hypopharyngeal+gland+with+an+age-dependent+role+change+of+the+worker+honeybee+(Apis+mellifera+L).">Expression of amylase and glucose oxidase in the hypopharyngeal gland with an age-dependent role change of the worker honeybee (Apis mellifera L).</a> Eur J Biochem. 265 (1), 127-133 (1999).</li><li>Ohashi, K., Sawata, M., Takeuchi, H., Natori, S., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+cloning+of+cDNA+and+analysis+of+expression+of+the+gene+for+alpha-glucosidase+from+the+hypopharyngeal+gland+of+the+honeybee+Apis+mellifera+L.">Molecular cloning of cDNA and analysis of expression of the gene for alpha-glucosidase from the hypopharyngeal gland of the honeybee Apis mellifera L.</a> Biochem Biophys Res Commun. 221 (2), 380-385 (1996).</li><li>Ueno, T., Nakaoka, T., Takeuchi, H., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+gene+expression+in+the+hypopharyngeal+glands+of+worker+honeybees+(Apis+mellifera+L.)+associated+with+an+age-dependent+role+change.">Differential gene expression in the hypopharyngeal glands of worker honeybees (Apis mellifera L.) associated with an age-dependent role change.</a> Zoolog Sci. 26 (8), 557-563 (2009).</li><li>Robinson, G. E., Page, R. E., Strambi, C., Strambi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hormonal+and+genetic+control+of+behavioral+integration+in+honey+bee+colonies.">Hormonal and genetic control of behavioral integration in honey bee colonies.</a> Science. 246 (4926), 109-112 (1989).</li><li>Sullivan, J. P., Fahrbach, S. E., Robinson, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Juvenile+hormone+paces+behavioral+development+in+the+adult+worker+honey+bee.">Juvenile hormone paces behavioral development in the adult worker honey bee.</a> Horm Behav. 37 (1), 1-14 (2000).</li><li>Ben-Shahar, Y., Robichon, A., Sokolowski, M. B., Robinson, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+gene+action+across+different+time+scales+on+behavior.">Influence of gene action across different time scales on behavior.</a> Science. 296 (5568), 741-744 (2002).</li><li>Lehman, H. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Division+of+labor+in+the+honey+bee+(Apis+mellifera):+the+role+of+tyramine+beta-hydroxylase.">Division of labor in the honey bee (Apis mellifera): the role of tyramine beta-hydroxylase.</a> J Exp Biol. 209 (Pt 14), 2774-2784 (2006).</li><li>Mutti, N. S., Wang, Y., Kaftanoglu, O., Amdam, G. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Honey+bee+PTEN--description,+developmental+knockdown,+and+tissue-specific+expression+of+splice-variants+correlated+with+alternative+social+phenotypes).">Honey bee PTEN--description, developmental knockdown, and tissue-specific expression of splice-variants correlated with alternative social phenotypes).</a> PLoS One. 6 (7), e22195 (2011).</li><li>Whitfield, C. W., Cziko, A. M., Robinson, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+expression+profiles+in+the+brain+predict+behavior+in+individual+honey+bees.">Gene expression profiles in the brain predict behavior in individual honey bees.</a> Science. 302 (5643), 296-299 (2003).</li><li>Ueno, T., Takeuchi, H., Kawasaki, K., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+the+Gene+Expression+Profiles+of+the+Hypopharyngeal+Gland+of+Worker+Honeybees+in+Association+with+Worker+Behavior+and+Hormonal+Factors.">Changes in the Gene Expression Profiles of the Hypopharyngeal Gland of Worker Honeybees in Association with Worker Behavior and Hormonal Factors.</a> PLoS One. 10 (6), e0130206 (2015).</li><li>Paul, R. K., Takeuchi, H., Matsuo, Y., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+expression+of+ecdysteroid-regulated+gene+E74+of+the+honeybee+in+ovary+and+brain.">Gene expression of ecdysteroid-regulated gene E74 of the honeybee in ovary and brain.</a> Insect Mol Biol. 14 (1), 9-15 (2005).</li><li>Takeuchi, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+novel+gene,+Mblk-1,+that+encodes+a+putative+transcription+factor+expressed+preferentially+in+the+large-type+Kenyon+cells+of+the+honeybee+brain.">Identification of a novel gene, Mblk-1, that encodes a putative transcription factor expressed preferentially in the large-type Kenyon cells of the honeybee brain.</a> Insect Mol Biol. 10 (5), 487-494 (2001).</li><li>Takeuchi, H., Paul, R. K., Matsuzaka, E., Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EcR-A+expression+in+the+brain+and+ovary+of+the+honeybee+(Apis+mellifera+L).">EcR-A expression in the brain and ovary of the honeybee (Apis mellifera L).</a> Zoolog Sci. 24 (6), 596-603 (2007).</li><li>Yamane, T., Miyatake, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduced+female+mating+receptivity+and+activation+of+oviposition+in+two+Callosobruchus+species+due+to+injection+of+biogenic+amines.">Reduced female mating receptivity and activation of oviposition in two Callosobruchus species due to injection of biogenic amines.</a> Journal of Insect Physiology. 56 (3), 271-276 (2010).</li><li>Ben-Shahar, Y., Leung, H. T., Pak, W. L., Sokolowski, M. B., Robinson, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=cGMP-dependent+changes+in+phototaxis:+a+possible+role+for+the+foraging+gene+in+honey+bee+division+of+labor.">cGMP-dependent changes in phototaxis: a possible role for the foraging gene in honey bee division of labor.</a> J Exp Biol. 206 (Pt 14), 2507-2515 (2003).</li><li>Danforth, B. N., Ji, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elongation+factor-1+alpha+occurs+as+two+copies+in+bees:+implications+for+phylogenetic+analysis+of+EF-1+alpha+sequences+in+insects.">Elongation factor-1 alpha occurs as two copies in bees: implications for phylogenetic analysis of EF-1 alpha sequences in insects.</a> Mol Biol Evol. 15 (3), 225-235 (1998).</li><li>Pandey, A., Bloch, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Juvenile+hormone+and+ecdysteroids+as+major+regulators+of+brain+and+behavior+in+bees.">Juvenile hormone and ecdysteroids as major regulators of brain and behavior in bees.</a> Current Opinion in Insect Science. 12, 26-37 (2015).</li></ol>

Preparation of single-cohort colonies
Here we described the protocol used in our previous study16 to prepare single-cohort colonies for analysis of HPG physiology associated with the shift in the role of worker bees. Nurse bees and precocious foragers that satisfied the criteria described in procedures 1.6-1.7 and Figure 2 were observed in the single-cohort colonies (Table 1). The photographs in Figure 2 would be useful in classific...

The European honeybee, Apis mellifera, is a eusocial insect with a highly organized society1. Worker honeybees (labor caste) are engaged in various tasks to maintain colony activity, and these tasks change according to the worker honeybee&#39;s age after eclosion, which is referred to as age-related division of labor2-4. Young workers (&#60;13 days old) take care of the brood in the hive by secreting royal jelly (nurse bees), while older workers (&#62;15 days old) collect nectar and pollen outside of the hive (foragers)2-4. The physiology of the workers changes in association with this role shift. For example, the function of the hypopharyngeal glands (HPGs), paired exocrine glands located in the head, changes in association with the role shift from nursing to foraging2,5. Nurse bee HPGs mainly synthesize major royal jelly proteins, which are major components of bee milk. On the other hand, forager HPGs mainly synthesize carbohydrate-metabolizing enzymes, such as &#945;-glucosidase III, to process nectar into honey by converting sucrose into glucose and fructose. Our previous studies revealed that the expression of mrjp2, which encodes a major royal jelly protein, and Hbg3, which encodes &#945;-glucosidase III, changes during the role shift6-9.
To determine whether the physiological changes in the worker tissues, including the HPGs, is associated with the role shift or with the age of the workers, it would be useful to manipulate the population composition of a honeybee colony, such as to prepare single-cohort colonies in which workers of almost the same age perform different tasks10,11. Robinson et al. (1989) described a method for establishing a single-cohort colony10. Single-cohort colonies initially comprise a queen and 0-2 day old workers. Several days after establishing the colonies, workers of almost the same age assume different tasks. Some workers perform nursing tasks as in typical colonies, whereas other workers perform foraging tasks earlier than usual and are thus called precocious foragers. Gene expression comparisons between nurse bees and precocious foragers would provide useful information about the role-associated physiology of worker tissues12-16. Here, we describe a detailed protocol for preparing single-cohort colonies for analysis of the role- and/or age-associated physiology of HPGs16. We also briefly describe how to examine the gene expression of mrjp2 and Hbg3 by quantitative reverse transcription-polymerase chain reaction (RT-PCR) to evaluate HPG physiology.
In addition to the analysis of worker physiology in single-cohort colonies, examination of the endocrine system is important for analyzing the regulatory mechanisms of role-associated worker physiology. Juvenile hormone (JH), which is known as the &#39;status quo&#39; hormone in insect larvae, accelerates the shift in the role from nursing to foraging in worker honeybees11. Furthermore, ecdysone, which is known as the molting hormone during metamorphosis, might be involved in the role shift as genes encoding ecdysone signaling molecules are expressed in the mushroom bodies, a higher center of the worker brain17-19. Therefore, we also describe the detailed protocol used in our previous study16 to treat workers with 20E, which is an active form of ecdysone, and methoprene, a JH analogue, for analysis of the effect of the endocrine system on HPG physiology (expression of mrjp2 and Hbg3).

<table border="0" cellpadding="0" cellspacing="0" width="769">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:231px;">UNIPOSCA</td>
			<td style="width:120px;">Mitsubishi pencil</td>
			<td style="width:91px;">PC-5M</td>
			<td style="width:327px;">Marker pen for the application of marks to bees&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">20-hydroxyecdysone</td>
			<td>Sigma Aldrich</td>
			<td>H5142</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Methoprene</td>
			<td>Sigma Aldrich</td>
			<td>33375</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Breeding case insect</td>
			<td>IRIS OHYAMA</td>
			<td>CP-SS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Electromotion mixier&#160;</td>
			<td>ISO</td>
			<td>23M-R25</td>
			<td>homogenization of tissue</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TRIZol Reagent</td>
			<td>Invitrogen</td>
			<td>15596-026</td>
			<td>the reagent for total RNA extraction</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DNase I&#160;</td>
			<td>Takara</td>
			<td>2270A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PrimeScript RT reagent kit</td>
			<td>Takara</td>
			<td>RR037A</td>
			<td>the reagent for reverse transcription</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SYBR Premix ExTaq II</td>
			<td>Takara</td>
			<td>RR820A</td>
			<td>the reagent for real-time PCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">LightCycle 1.2 Instrument</td>
			<td>Roche</td>
			<td>12011468001</td>
			<td>the instrument for real-time PCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">LightCycle Capillaries (20&#956;l)</td>
			<td>Roche</td>
			<td>4929292001</td>
			<td>the material for real-time PCR</td>
		</tr>
	</tbody>
</table>

preparation of single-cohort colonies and hormone treatment of worker honeybees to analyze physiology associated with role and/or endocrine system

Honeybee workers are engaged in various tasks related to maintaining colony activity. The tasks of the workers change according to their age (age-related division of labor). Young workers are engaged in nursing the brood (nurse bees), while older workers are engaged in foraging for nectar and pollen (foragers). The physiology of the workers changes in association with this role shift. For example, the main function of the hypopharyngeal glands (HPGs) changes from the secretion of major royal jelly proteins (MRJPs) to the secretion of carbohydrate-metabolizing enzymes. Because worker tasks change as the workers age in typical colonies, it is difficult to discriminate the physiological changes that occur with aging from those that occur with the role shift. To study the physiological changes in worker tissues, including the HPGs, in association with the role shift, it would be useful to manipulate the honeybee colony population by preparing single-cohort colonies in which workers of almost the same age perform different tasks. Here we describe a detailed protocol for preparing single-cohort colonies for this analysis. Six to eight days after single-cohort colony preparation, precocious foragers that perform foraging tasks earlier than usual appear in the colony. Representative results indicated role-associated changes in HPG gene expression, suggesting role-associated HPG function. In addition to manipulating the colony population, analysis of the endocrine system is important for investigating role-associated physiology. Here, we also describe a detailed protocol for treating workers with 20-hydroxyecdysone (20E), an active form of ecdysone, and methoprene, a juvenile hormone analogue. The survival rate of treated bees was sufficient to examine gene expression in the HPGs. Gene expression changes were observed in response to 20E- and/or methoprene-treatment, suggesting that hormone treatments induce physiological changes of the HPGs. The protocol for hormone treatment described here is appropriate for examining hormonal effects on worker physiology.

An overview of the protocol for preparing single-cohort colonies is illustrated in Figure 1A. Time-course of experiments from preparing single-cohort colonies to sample collection is shown in Figure 1B. Workers that satisfied the behavioral criteria for nursing behavior or foraging behavior were collected from single-cohort colonies, and HPG development was estimated in these workers. Table 1 shows the classification of HPG development in...

Watch this Scientific Journal Video about Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System at JoVE.com

Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System

Here we describe our detailed protocol for the preparation of single-cohort honeybee colonies&#160;&#8211; a useful tool for analyzing the role-associated worker physiology. We also describe detailed protocols for treating workers with juvenile hormone and ecdysone to evaluate the involvement of these hormones in the regulation of worker behavior and/or physiology.

Honeybee workers are engaged in various tasks related to maintaining colony activity. The tasks of the workers change according to their age (age-related ...

The overall goal of these procedures is to examine the physiology of worker honeybees in association with the workers'role and the status of their endocrine system. It's a method which has been widely used for the analysis of worker behavior, can also help answer key questions about the relationship between physiology and the role of worker honeybees. The main advantage of this technique is that it is relatively easy to perform.To create two single-cohort colonies, begin with three standard colonies and collect newly-emerged worker bees from each of the three. Using tweezers, regularly inspect the colonies for the appearance of puby in the capped peripheral cells with brown eyes and pigmented cuticles. Once found, most of the puby will emerge in the next few days.Then brush the adults off the combs and remove the combs from the colony. Combine one such comb from each of the three colonies into an empty nuclear hive box. Establish two such hive boxes and incubate them at 33 degrees Celsius with a relative humidity of at least 60%Over the next three days, collect about 3, 000 newly-emerged workers from each new hive box.To approximate the number of bees in each collection, weigh five randomly selected newly-emerged workers and use their average mass compared to the mass of the collected workers to estimate the number of bees. Prepare new hive boxes with a comb that is loaded with honey and pollen from an unmanipulated colony and another comb that is empty. Next, label the thoraxes of approximately 900 workers in each new colony using water-based poster paint markers.Then transfer the collection of worker bees into these new hive boxes and add one queen. Six to eight days after setting up the single-cohort colonies, collect some of their nurse bees and precocious foragers for analysis. To collect the nurse bees, use tweezers to select bees that put their heads into comb cells to care for the brood.Pick them up by the thorax. To collect foragers, use an insect net to capture workers that return to their hives with pollen loads on their hind legs. To classify the HPGs of honeybees, transfer a collection of 10 to 15 bees to an insect cage and anesthetize them at four degrees Celsius for 10 to 15 minutes until the bees cannot fly or walk.Then transfer the bees onto ice to cool them into a completely anesthetized state after about five minutes. Then leave the bees on ice until needed. Now, dissect their heads from their bodies with scissors and tweezers.In a Petri dish, fix the heads into dental wax using insect pins. To do this, use two pins inserted into the base of the antennae. Now, soak the fixed heads in insect saline and transfer the dish to a stereoscope.Using fine tweezers and a surgical knife, remove the anterior cuticle from the head to access the areas around the brain. Next, remove the white membranous tracheal tissue under the cuticle to expose the HPGs. Then dissect the HPGs from the head by slowing pulling them out using tweezers.Classify the HPGs with large and circular aseni developed and consider them to be from nurse bees. Classify HPGs with small and distorted aseni as shrunken and consider these to come from forager bees. Classify HPGs corresponding to neither developed nor shrunken as intermediate.Use the developed and shrunken HPGs for RNA extraction to compare their gene expression. Collect nurse bees from typical colonies as previously described. Anesthetize the nurse bees at four degrees Celsius for about 30 minutes.Then using tweezers, immobilize the bees on dental wax on a Petri dish. Once immobilized, inject the heads of the nurse bees with one microliter of 20E solution. To do this, use a calibrated capillary micropipette.Connect the injection tip to a rubber tube and connect the 200 microliter micropipette tip to the opposite end of the tube. Next, load one microliter of 20E solution onto a piece of parafilm. Then use mouth aspiration to draw the solution into the injection tip.Next, insert the injection tip into the base of the antennae and inject the solution by exhaling on the tube. Alternatively, use an automated injection machine if available. Rear the injected bees in insect cages at 35 degrees Celsius under dark and humid conditions.Include honey water for nourishment and track survivorship as needed. Collect combs containing puby from a colony and incubate them at 35 degrees Celsius with 60%or more relative humidity for up to one day. Collect the newly-emerged bees from the combs and apply paint marks to their thoraxes using poster paint.Then return these bees to their colonies. After six days, collect the painted workers from the colonies and anesthetize them at four degrees Celsius for 30 minutes. Once anesthetized, immobilize the bees using tweezers and dental wax as previously described.Then apply one to five microliters of methoprene and acetone onto their heads using a micropipette resistant to acetone. Rear the bees in cages as previously described. If a high mortality is observed, reduce the volume of acetone to one microliter.Workers that satisfy the behavioral criteria for nursing behavior or foraging behavior were collected from single-cohort colonies and their HPG development was estimated. Based on the HPG RNA extractions and quantitative RTPCR, expression of MRJP2 was enriched in nurse bees and Hbg3 was enriched in precocious foragers. Selected workers were injected with 20E and surviving bees were counted.Seven days after injection, approximately 60%to 80%of injected bees were alive. The control injection had similar results. Quantitative RTPCR analysis show that the 20E injection decreased expression of MRJP2 in the HPGs.The same occurred with Hbg3 in the HPGs. In addition to 20E, the effect of topical methoprene application on MRJP2 and Hbg3 expression in the HPGs was examined. After topical application, most bees survived to seven days.RNA harvested from these survivors show that application of methoprene inhibited the expression of MRJP2 and enhanced the expression of Hbg3. After watching this video, you should have a good understanding of how to prepare single-cohort colonies and treat the bees with hormone in order to analyze the worker physiology associated with roles and endocrine system. Once mastered, the and the classification of HPG can be done in five minutes if it is performed properly.While attempting the injection for hormone solution, it's important to remember to minimize the damage of bees by anesthesia and injection in order to keep bees alive when reared. Don't forget that working with honeybees can be hazardous and precautions such as wearing bee suits and gloves should always be taken while performing collection of bees and manipulation of colonies.

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Simultaneous Long-term Recordings at Two Neuronal Processing Stages in Behaving Honeybees

In both mammals and insects neuronal information is processed in different higher and lower order brain centers. These centers are coupled via convergent and divergent anatomical connections including feed forward and feedback wiring. Furthermore, information of the same origin is partially sent via parallel pathways to different and sometimes into the same brain areas. To understand the evolutionary benefits as well as the computational advantages of these wiring strategies and especially their temporal dependencies on each other, it is necessary to have simultaneous access to single neurons of different tracts or neuropiles in the same preparation at high temporal resolution. Here we concentrate on honeybees by demonstrating a unique extracellular long term access to record multi unit activity at two subsequent neuropiles1, the antennal lobe (AL), the first olfactory processing stage and the mushroom body (MB), a higher order integration center involved in learning and memory formation, or two parallel neuronal tracts2 connecting the AL with the MB.&#160;The latter was chosen as an example and will be described in full. In the supporting video the construction and permanent insertion of flexible multi&#160;channel wire electrodes is demonstrated. Pairwise differential amplification of the micro&#160;wire electrode channels drastically reduces the noise and verifies that the source of the signal is closely related to the position of the electrode tip. The mechanical flexibility of the used wire electrodes allows stable invasive long&#160;term recordings over many hours up to days, which is a clear advantage compared to conventional extra&#160;and intracellular in vivo recording techniques.

Simultaneous extracellular long term recordings from two different brain neuropiles or two different anatomical tracts were established in honeybees. These recordings allow the investigation of temporal aspects of neuronal processing across different brain areas at the single neuron as well as at the ensemble level in a behaving animal.

In both mammals and insects neuronal information is processed in different higher and lower order brain centers. These centers are coupled via convergent ...

Live Imaging of Nicotine Induced Calcium Signaling and Neurotransmitter Release Along Ventral Hippocampal Axons

Sustained enhancement of axonal signaling and increased neurotransmitter release by the activation of pre-synaptic nicotinic acetylcholine receptors (nAChRs) is an important mechanism for neuromodulation by acetylcholine (ACh). The difficulty with access to probing the signaling mechanisms within intact axons and at nerve terminals both in vitro and in vivo has limited progress in the study of the pre-synaptic components of synaptic plasticity. Here we introduce a gene-chimeric preparation of ventral hippocampal (vHipp)&#8211;accumbens (nAcc) circuit in vitro that allows direct live imaging to analyze both the pre- and post-synaptic components of transmission while selectively varying the genetic profile of the pre- vs post-synaptic neurons. We demonstrate that projections from vHipp microslices, as pre-synaptic axonal input, form multiple, reliable glutamatergic synapses with post-synaptic targets, the dispersed neurons from nAcc. The pre-synaptic localization of various subtypes of nAChRs are detected and the pre-synaptic nicotinic signaling mediated synaptic transmission are monitored by concurrent electrophysiological recording and live cell imaging. This preparation also provides an informative approach to study the pre- and post-synaptic mechanisms of glutamatergic synaptic plasticity in vitro.

We developed a gene-chimeric preparation of ventral hippocampal &#8211; accumbens circuit in vitro that allows direct live imaging to analyze presynaptic mechanisms of nicotinic acetylcholine receptors (nAChRs) mediated synaptic transmission. This preparation also provides an informative approach to study the pre- and post-synaptic mechanisms of synaptic plasticity.

Sustained enhancement of axonal signaling and increased neurotransmitter release by the activation of pre-synaptic nicotinic acetylcholine receptors ...

Utilizing Combined Methodologies to Define the Role of Plasma Membrane Delivery During Axon Branching and Neuronal Morphogenesis

During neural development, growing axons extend to multiple synaptic partners by elaborating axonal branches. Axon branching is promoted by extracellular guidance cues like netrin-1 and results in dramatic increases to the surface area of the axonal plasma membrane. Netrin-1-dependent axon branching likely involves temporal and spatial control of plasma membrane expansion, the components of which are supplied through exocytic vesicle fusion. These fusion events are preceded by formation of SNARE complexes, comprising a v-SNARE, such as VAMP2 (vesicle-associated membrane protein 2), and plasma membrane t-SNAREs, syntaxin-1 and SNAP25 (synaptosomal-associated protein 25). Detailed herein isa multi-pronged approach used to examine the role of SNARE mediated exocytosis in axon branching. The strength of the combined approach is data acquisition at a range of spatial and temporal resolutions, spanning from the dynamics of single vesicle fusion events in individual neurons to SNARE complex formation and axon branching in populations of cultured neurons. This protocol takes advantage of established biochemical approaches to assay levels of endogenous SNARE complexes and Total Internal Reflection Fluorescence (TIRF) microscopy of cortical neurons expressing VAMP2 tagged with a pH-sensitive GFP (VAMP2-pHlourin) to identify netrin-1 dependent changes in exocytic activity in individual neurons. To elucidate the timing of netrin-1-dependent branching, time-lapse differential interference contrast (DIC) microscopy of single neurons over the order of hours is utilized. Fixed cell immunofluorescence paired with botulinum neurotoxins that cleave SNARE machinery and block exocytosis demonstrates that netrin-1 dependent axon branching requires SNARE-mediated exocytic activity.

Light microscopy techniques coupled with biochemical assays elucidate the involvement of SNARE-mediated exocytosis in netrin-dependent axon branching. This combination of techniques permits identification of molecular mechanisms controlling axon branching and cell shape change.

During neural development, growing axons extend to multiple synaptic partners by elaborating axonal branches. Axon branching is promoted by extracellular ...

Video Imaging and Spatiotemporal Maps to Analyze Gastrointestinal Motility in Mice

The enteric nervous system (ENS) plays an important role in regulating gastrointestinal (GI) motility and can function independently of the central nervous system. Changes in ENS function are a major cause of GI symptoms and disease and may contribute to GI symptoms reported in neuropsychiatric disorders including autism. It is well established that isolated colon segments generate spontaneous, rhythmic contractions known as Colonic Migrating Motor Complexes (CMMCs). A procedure to analyze the enteric neural regulation of CMMCs in ex vivo preparations of mouse colon is described. The colon is dissected from the animal and flushed to remove fecal content prior to being cannulated in an organ bath. Data is acquired via a video camera positioned above the organ bath and converted to high-resolution spatiotemporal maps via an in-house software package. Using this technique, baseline contractile patterns and pharmacological effects on ENS function in colon segments can be compared over 3-4 hr. In addition, propagation length and speed of CMMCs can be recorded as well as changes in gut diameter and contraction frequency. This technique is useful for characterizing gastrointestinal motility patterns in transgenic mouse models (and in other species including rat and guinea pig). In this way, pharmacologically induced changes in CMMCs are recorded in wild type mice and in the Neuroligin-3R451C mouse model of autism. Furthermore, this technique can be applied to other regions of the GI tract including the duodenum, jejunum and ileum and at different developmental ages in mice.

This article describes a video imaging technique and high-resolution spatiotemporal mapping to identify changes in the neural regulation of colonic motility in adult mice. Subtle effects on gastrointestinal (GI) function can be detected using this approach in isolated tissue preparations to advance our understanding of GI disease.

The enteric nervous system (ENS) plays an important role in regulating gastrointestinal (GI) motility and can function independently of the central ...

Methods and Tips for Intravenous Administration of Adeno-associated Virus to Rats and Evaluation of Central Nervous System Transduction

Adeno-associated virus (AAV) vectors are a key reagent in the neurosciences for clustered regularly interspaced short palindromic repeats (CRISPR), optogenetics, cre-lox targeting, etc. The purpose of this manuscript is to aid the investigator attempting expansive central nervous system (CNS) gene transfer in the rat via tail vein injection of AAV. Wide-scale expression is relevant for conditions with widespread pathology, and a rat model is significant due to its greater size and physiologic similarities to humans compared to mice. In this example application, a wide-scale neuronal transduction is used to mimic a neurodegenerative disease that affects the entire spinal cord, amyotrophic lateral sclerosis (ALS). The efficient wide-scale CNS transduction can also be used to deliver therapeutic protein factors in pre-clinical studies. After a post-injection expression interval of several weeks, the effects of the transduction are evaluated. For a green fluorescent protein (GFP) control vector, the amount of GFP in the cerebellum is estimated quickly and reliably by a basic imaging program. For motor disease phenotypes that are induced by the ALS related protein transactive response DNA-binding protein of 43 kDa (TDP-43), the deficits are scored by escape reflex and rotarod. Beyond disease modeling and gene therapy, there are diverse potential applications for the wide-scale gene targeting described here. The expanded use of this method will aid in expediting hypothesis testing in the neurosciences and neurogenetics.

Methods for a wide-scale central nervous system gene delivery in the rat are covered. In this example, the purpose is to mimic a disease that affects the entire spinal cord. The widespread transduction can be used to deliver a therapeutic protein to the CNS from a one-time, peripheral administration.

Adeno-associated virus (AAV) vectors are a key reagent in the neurosciences for clustered regularly interspaced short palindromic repeats (CRISPR), ...

Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution. We modified the original Slater-Hammel (S-H) stop signal task to create a &#34;racecar&#34; version with TMS pulses time-locked to intra-trial events. This task is self-paced, with each trial initiating after a button push to move the racecar towards the 800 ms target. GO trials require a finger-lift to stop the racecar just before this target. Interspersed randomly are STOP trials (25%) during which the dynamically adjusted stop signal prompts subjects to prevent finger-lift. For GO trials, TMS pulses were delivered at 650 ms after trial onset; whereas, for STOP trials, the TMS pulses occurred 150 ms after the stop signal. The timings of the TMS pulses were decided based on electroencephalography (EEG) studies showing event-related changes in these time ranges during stop signal tasks. This task was studied in 3 blocks at two study sites (n=38) and we recorded behavioral performance and event-related motor-evoked potentials (MEP). Regression modelling was used to analyze MEP amplitudes using age as a covariate with multiple independent variables (sex, study site, block, TMS pulse condition [single- vs. paired-pulse], trial condition [GO, successful STOP, failed STOP]). The analysis showed that TMS pulse condition (p&#60;0.0001) and its interaction with trial condition (p=0.009) were significant. Future applications for this online S-H/TMS paradigm include the addition of simultaneous EEG acquisition to measure TMS-evoked EEG potentials. A potential limitation is that in children, the TMS pulse sound could&#160;affect behavioral task performance.

We describe an experimental procedure to quantify excitability and inhibition of primary motor cortex during a motor response inhibition task by using Transcranial Magnetic Stimulation throughout the course of a Stop Signal Task.

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) ...

Convection Enhanced Delivery of Optogenetic Adeno-associated Viral Vector to the Cortex of Rhesus Macaque Under Guidance of Online MRI Images

In non-human primate (NHP) optogenetics, infecting large cortical areas with viral vectors is often a difficult and time-consuming task. Here, we demonstrate the use of magnetic resonance (MR)-guided convection enhanced delivery (CED) of optogenetic viral vectors into primary somatosensory (S1) and motor (M1) cortices of macaques to obtain efficient, widespread cortical expression of light-sensitive ion channels. Adeno-associated viral (AAV) vectors encoding the red-shifted opsin C1V1 fused to yellow fluorescent protein (EYFP) were injected into the cortex of rhesus macaques under MR-guided CED. Three months post-infusion, epifluorescent imaging confirmed large regions of optogenetic expression (&#62;130 mm2) in M1 and S1 in two macaques. Furthermore, we were able to record reliable light-evoked electrophysiology responses from the expressing areas using micro-electrocorticographic arrays. Later histological analysis and immunostaining against the reporter revealed widespread and dense optogenetic expression in M1 and S1 corresponding to the distribution indicated by epifluorescent imaging. This technique enables us to obtain expression across large areas of the cortex within a shorter period of time with minimal damage compared to the traditional techniques and can be an optimal approach for optogenetic viral delivery in large animals such as NHPs. This approach demonstrates great potential for network-level manipulation of neural circuits with cell-type specificity in animal models evolutionarily close to humans.&#160;

Here, we demonstrate magnetic resonance (MR)-guided convection enhanced delivery (CED) of viral vectors into the cortex as an efficient and simplified approach for achieving optogenetic expression across large cortical areas in the macaque brain.

In non-human primate (NHP) optogenetics, infecting large cortical areas with viral vectors is often a difficult and time-consuming task. Here, we ...

Generation of 3-D Collagen-based Hydrogels to Analyze Axonal Growth and Behavior During Nervous System Development

This protocol uses natural type I collagen to generate three-dimensional (3-D) hydrogel for monitoring and analyzing the axonal growth. The protocol is centered on culturing small pieces of embryonic or early postnatal rodent brains inside a 3-D hydrogel formed by the rat tail tendon-derived type I collagen with specific porosity. Tissue pieces are cultured inside the hydrogel and confronted to specific brain fragments or genetically-modified cell aggregates to produce and secrete molecules suitable for creating a gradient inside the porous matrix. The steps of this protocol are simple and reproducible but include critical steps to be considered carefully during its development. Moreover, the behavior of growing axons can be monitored and analyzed directly using a phase-contrast microscope or mono/multiphoton fluorescence microscope after fixation by immunocytochemical methods.

Here, we provide a method for analyzing the behavior of growing axons in 3D matrices, mimicking their natural development.

This protocol uses natural type I collagen to generate three-dimensional (3-D) hydrogel for monitoring and analyzing the axonal growth. The protocol is ...

Preparation of Acute Human Hippocampal Slices for Electrophysiological Recordings

Epilepsy affects about 1% of the world population and leads to a severe decrease in quality of life due to ongoing seizures as well as high risk for sudden death. Despite an abundance of available treatment options, about 30% of patients are drug-resistant. Several novel therapeutics have been developed using animal models, though the rate of drug-resistant patients remains unaltered. One of probable reasons is the lack of translation between rodent models and humans, such as a weak representation of human pharmacoresistance in animal models. Resected human brain tissue as a preclinical evaluation tool has the advantage to bridge this translational gap. Described here is a method for high quality preparation of human hippocampal brain slices and subsequent stable induction of epileptiform activity. The protocol describes the induction of burst activity during application of 8 mM KCl and 4-aminopyridin. This activity is sensitive to established AED lacosamide or novel antiepileptic candidates, such as dimethylethanolamine (DMEA). In addition, the method describes induction of seizure-like events in CA1 of human hippocampal brain slices by reduction of extracellular Mg2+ and application of bicuculline, a GABAA receptor blocker. The experimental set-up can be used to screen potential antiepileptic substances for their effects on epileptiform activity. Furthermore, mechanisms of action postulated for specific compounds can be validated using this approach in human tissue (e.g., using patch-clamp recordings). To conclude, investigation of vital human brain tissue ex vivo (here, resected hippocampus from patients suffering from temporal lobe epilepsy) will improve the current knowledge of physiological and pathological mechanisms in the human brain.

The presented protocol describes the transport and preparation of resected human hippocampal tissue with the ultimate goal to use vital brain slices as a preclinical evaluation tool for potential antiepileptic substances.

Epilepsy affects about 1% of the world population and leads to a severe decrease in quality of life due to ongoing seizures as well as high risk for ...

Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of benign and malignant lesions through a natural anatomical extra-cranial pathway, represented by the nasal cavities, avoiding brain retraction and neurovascular manipulation. This is reflected by the patients' prompt clinical recovery and the low risk of permanent neurological sequelae, representing the main caveat of conventional skull base surgery. This surgery must be tailored to each specific case, considering its features and relationship with surrounding neural structures, mostly based on preoperative neuroimaging. Advanced MRI techniques, such as tractography, have been rarely adopted in skull base surgery due to technical issues: lengthy and complicated processes to generate reliable reconstructions for inclusion in the neuronavigation system. 
This paper aims to present the protocol implemented in the institution and highlights the synergistic collaboration and teamwork between neurosurgeons and the neuroimaging team (neurologists, neuroradiologists, neuropsychologists, physicists, and bioengineers) with the final goal of selecting the optimal treatment for each patient, improving the surgical results and pursuing the advancement of personalized medicine in this field.

We present a protocol to integrate diffusion MRI tractography in patient work-up to endoscopic endonasal surgery for a skull base tumor. The methods for adopting these neuroimaging studies in the pre- and intra-operative phases are described.

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of ...