The authors wish to acknowledge support from the National Institute of General Medical Sciences T32 GM063483-14 grant and Cincinnati Children&#39;s Research Foundation. For data adapted from Zoubovsky et al., 2019, Creative Common License can be found at the following location: http://creativecommons.org/licenses/by/4.0/.

All animal experiments described were approved by the Animal Care and Use Committee at Cincinnati Children&#39;s Medical Center and were in accordance with the National Institutes of Health guidelines. Ad libitum access to standard rodent chow and water was provided at all times to mice, including during the CGS paradigm. Mice were housed on a 14 h/10 h light-dark cycle (lights on 06:00 h) unless otherwise specified (i.e., exposure to lights overnight).
1. Preparing for timed matings
<ol>
	<li>At least 2 weeks prior to setting up timed matings, house the adult female mice together in a standard mouse cage (18.4 cm x 29.2 cm x 12.7 cm), four mice per cage. Label each female mouse with a specific ID number via an ear tag. 
	NOTE: C57BL6 female mice with no prior pregnancy and between 3 to 6 months of age were used for this protocol.</li>
	<li>At least 1 week prior to setting up timed matings, individually house the adult male mice to be used for mating.</li>
</ol>
2. Setting up timed matings
<ol>
	<li>Set up the timed matings at 18:00 h. Take two female mice and place them inside a cage that holds an individually housed male mouse. Separate the timed matings the following morning by 08:00 h.</li>
</ol>
3. Checking the copulatory plug, designated as gestational day 0.5 (G0.5)
<ol>
	<li>Immediately after separating timed matings, check for the presence of a copulatory plug in the female mice. The presence of a copulatory plug will mark G0.5. Allow the mouse to hold the wire grid inside the cage and gently lift it by the tail to visualize the vaginal opening. 
	NOTE: The presence of a copulatory plug indicates sexual activity has occurred but does not guarantee a pregnancy. When attempting to calculate the number of experimental mice needed, expect 50% of mice to be plugged from timed matings and a pregnancy to plug incidence of 60%-70%.</li>
	<li>Use simple visual examination to identify the presence of a copulatory plug (an opaque whitish hardened mass within or slightly protruding from the vaginal opening). If the copulatory plug is not easily identified by simple visual examination, gently insert a blunt end probe into the vaginal opening. Identify the plugs located further back in the vagina by the resistance of probe insertion.</li>
	<li>Separate the female mice with copulatory plugs and group house in standard mouse cages, 3 to 4 mice per cage.</li>
</ol>
4. Preparing for CGS paradigm
<ol>
	<li>Randomly assign cages housing female mice with copulatory plugs into two groups on G5.5: Control and CGS group. Attempt to randomize cages to have an approximately equal number of mice per group. Transfer the mice to clean standard mouse cages and label with a &#34;do not disturb&#34; sign. Designate these cages as &#34;home cages&#34; for mice to place them at the end of each stressor.</li>
	<li>Designate a separate room in the mouse facility to perform the CGS paradigm. Design a 11-day stressor regimen, which runs from G6.5 to G17.5, to utilize each of the 7 day stressors [exposure to foreign objects (marbles or legos), predator odor exposure (dirty rat bedding), 30&#176; cage tilt, frequent changes of bedding, bedding removal, movement on shaker] twice per day, and to utilize each of the 3 night stressors (overnight lights on, cage mate change, exposure to wet bedding) overnight in a random fashion. For a possible sample schedule and schematic of experiments described below, see Figure 1. 
	NOTE: Each day stressor should fall within the light cycle of mice (lights on 06:00 h-20:00 h), and last 2 h, with at least a 2 h break in between stressors. Each night stressor should be set up at the beginning of the dark cycle (lights off 20:00 h) and separated at the start of light cycle (lights on 06:00 h).</li>
</ol>
5. Performing the CGS paradigm
<ol>
	<li>Set up specific stressors on a standard static cage with filtered top and water bottle in the room designated for the CGS paradigm. Prepare the number of static cages needed for the experiment depending on the number of mouse cages designated to undergo CGS during randomization. Before starting each stressor, transfer the mouse cages of the CGS group from the housing room to the CGS room. 
	NOTE: Perform the handling/transfer of mice from home cage to experimental cage and back in laminar flow hoods.</li>
	<li>Apply the following stressors according to the pre-designed regimen (refer to step 4.2).
	<ol>
		<li>Exposure to foreign objects (marbles or legos): Place six marbles (14 mm in diameter) or six legos (different shapes, not to exceed 4 cm in height) randomly distributed into a clean static cage with mouse bedding, without including the mouse nestlets. Place the mice together with their home cage counterparts into the static cage with foreign objects for 2 h. Return the mice to their home cage with the same counterparts at the conclusion of the stressor. 
		NOTE: Clean the foreign objects after use.</li>
		<li>Predator odor exposure (dirty rat bedding): Place 1 cm in depth of fresh dirty rat bedding from female rats into a clean static cage with no mouse bedding, without including the mouse nestlets. Place the mice together with their home cage counterparts into the static cage with dirty rat bedding for 2 h. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
		<li>30&#176; cage tilt: Place the mice with their home cage counterparts into a clean static cage with mouse bedding, without including the mouse nestlets. Tilt the cage at 30&#176; against the wall for 2 h. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
		<li>Frequent changes of bedding: Place the mice with their home cage counterparts into a clean static cage with mouse bedding, without including the mouse nestlets. Substitute the mouse bedding with clean mouse bedding every 10 min for 2 h. During mouse bedding changes, gently place the mice in a different clean cage to avoid direct contact with the mice. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
		<li>Bedding removal: Place the mice together with their home cage counterparts into an empty clean static cage (with no mouse bedding or nestlets) for 2 h. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
		<li>Movement on shaker: Place the mice with their home cage counterparts into a clean static cage with mouse bedding, without including the mouse nestlets. Place the static cage atop a reciprocal lab shaker set to 140 strokes per min for 2 h. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
		<li>Overnight exposure to lights: Place the mice with their home cage counterparts into a clean static cage with mouse bedding, without including the mouse nestlets. Keep the lights on overnight (20:00 h-06:00 h) to interfere with dark cycle. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
		<li>Cage mate change: Transfer the mouse into a clean static cage with mouse bedding which is being housed by a different group of two female mice (intact females not part of treatment or control group). Keep the mouse in the static cage with unfamiliar cage mates overnight. Return the mouse to its home cage with its specific home cage counterparts at the conclusion of the stressor.</li>
		<li>Exposure to wet bedding: Fill the static cage with mouse bedding with clean water kept at 24 &#176;C until bedding is saturated with water. Place the mice together with their home cage counterparts into the static cage with wet bedding overnight. Return the mice to their home cage with the same counterparts at the conclusion of the stressor.</li>
	</ol>
	</li>
	<li>During CGS paradigm, keep the control mice undisturbed in their home cages inside the housing room.</li>
	<li>Replace the used home cages with new home cages on G10.5. On G17.5, at the conclusion of the overnight stressor, single-house all the experimental mice to prepare for parturition and downstream functional assessments.</li>
</ol>
6. Monitoring the experimental mice during the CGS paradigm
<ol>
	<li>Monitor the mice every 1 h during stressor application, except during overnight stressors.</li>
	<li>Exclude the mice displaying distress signs, including wounds, lethargy, or any physical abnormality from the experiment. Contact the veterinary staff as needed.</li>
</ol>
7. Measuring the percentage body weight gain during gestation in the experimental mice (optional)
<ol>
	<li>On G6.5, weigh the mice individually before the exposure to stressors. On G17.5, at the conclusion of the overnight stressor, weigh the mice individually. Weigh the control mice at the equivalent gestational time points.</li>
	<li>Measure the percentage body weight gain during gestation by setting the weight of the first day of the CGS paradigm (G6.5) as 100%.</li>
</ol>
8. Measuring the postpartum relative adrenal gland weights in experimental mice (optional)
<ol>
	<li>On postpartum day 2 (PP2), weigh the control and the CGS dams individually. Euthanize the dams by carbon dioxide inhalation&#160;followed by cervical dislocation in a fume hood.</li>
	<li>Place the mice on a dissection plate, sterilize the abdominal area with 70% ethanol, and open the abdominal cavity using scissors to make a vertical cut. Isolate the adrenal glands located adjacent to the anterior pole of the kidneys with forceps, bilaterally. Carefully dissect the fat tissue surrounding the adrenal glands underneath a dissecting microscope.</li>
	<li>Weigh the bilateral adrenal glands individually. Calculate the relative adrenal gland weights in milligrams per gram (total weight of the right and the left adrenal glands/body weight).</li>
</ol>
9. Measuring the postpartum hypothalamic pituitary adrenal (HPA) axis activity in the experimental mice (optional)
<ol>
	<li>In preparation for HPA axis measurements, euthanize&#160;litters to 6 pups per litter on postpartum day 0 (PP0). Use carbon dioxide inhalation, followed by decapitation with surgical scissors as a secondary method of euthanasia.</li>
	<li>On postpartum day 2 (PP2), individually restrain the control and the CGS dams inside a well-ventilated 50 mL polypropylene conical tube for 20 min. Immediately after restraint stress, remove the mouse from the conical tube and restrain the mouse with the non-dominant hand by holding the loose skin over the shoulders and posterior to the ears to have the skin over the mandible taut.</li>
	<li>Puncture the submandibular vein with a lancet slightly behind the mandible but anterior to the ear canal. Collect up to 100 &#181;L of maternal blood in a serum separator tube. After sample collection, apply gentle pressure with gauze to the puncture site to stop the bleeding. Return the dams to the home cage once the bleeding stops.</li>
	<li>Centrifuge the serum separator tube at 21,130 x g for 6 min and carefully remove the serum. Store the serum at -20 &#176;C for later use. Measure the serum corticosterone concentration by an ELISA kit following the manufacturer&#39;s protocol.</li>
</ol>
10. Measuring the postpartum behavioral changes in the experimental mice (optional)
<ol>
	<li>To prepare for the behavioral analysis, cull litters to 6 pups per litter on PP0.</li>
	<li>Perform analysis of the maternal care fragmentation from PP2 to PP5. On each day, during the light cycle, expose the dams to the testing room for a 5 min habituation period before videotaping the maternal behavior for a 30 min period.
	<ol>
		<li>Assess the maternal care fragmentation by measuring the average length of an individual licking/grooming bout and the total number of bouts performed by dams19. 
		NOTE: Licking/grooming behavior is defined as a behavior where the dam is making contact with the pup&#39;s body with her tongue, or the pup is being handled by the dam with her forepaws. A bout is defined as an uninterrupted period of time where the dam is engaged in licking/grooming of her pups.</li>
	</ol>
	</li>
	<li>Perform analysis of anhedonia via sucrose preference test (SPT) from PP0 to PP6. Expose the dams to one 100 mL bottle of clean water and one 100 mL bottle of 4% sucrose solution in their home cage. Measure the amount of water and sucrose consumed (in mL) daily. Interchange the bottle placement in the home cage. Calculate the sucrose preference using the averages from the last 4 days: preference % = [(sucrose consumption / sucrose + water consumption) x 100].</li>
	<li>Perform analysis of anxiety-like behavior via elevated zero maze (EZM) on PP8. Place the dams individually on the EZM apparatus consisting of two closed quadrants and two open quadrants elevated from the floor. Allow the dams to explore the maze undisturbed for 5 min. Quantify the time spent in the open quadrant and the number of entries into the open quadrants.</li>
</ol>
11. Measuring the postnatal offspring weight changes (optional)
<ol>
	<li>To prepare for the offspring weight analysis, cull litters to 6 pups per litter on the day of birth (postnatal day 0, PN0).</li>
	<li>Record the weight of pups on PN0 and at different time points during the postnatal period (PN2, 7, 15, 21).</li>
</ol>

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V., Neumann, I. D., Reber, S. O., Slattery, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-fat+diet+prevents+adaptive+peripartum-associated+adrenal+gland+plasticity+and+anxiolysis.">High-fat diet prevents adaptive peripartum-associated adrenal gland plasticity and anxiolysis.</a> Scientific Reports. 5, 14821-14831 (2015).</li><li>Nugent, B. M., Bale, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+omniscient+placenta:+metabolic+and+epigenetic+regulation+of+fetal+programming.">The omniscient placenta: metabolic and epigenetic regulation of fetal programming.</a> Frontiers in Neuroendocrinology. 39, 28-37 (2015).</li></ol>

The authors have no conflicts of interest to disclose.

Exposing the pregnant mice to CGS perturbs postpartum maternal neuroendocrine function, including HPA axis response to novel stressors, and is associated with various behavioral abnormalities relevant to perinatal mood and anxiety disorders. Given that the model employs utilization of an environmental risk factor, higher phenotypic variation is expected than otherwise observed in genetic models22. Nevertheless, results obtained from application of the CGS paradigm can be consistent across research...

The mechanisms underlying increased susceptibility to neuropsychiatric disorders in mothers and infants following adverse maternal exposures in the peripartum period remain largely unknown. Substantial maternal physiological alterations occur during pregnancy and the transition to the postpartum period, including several neuroendocrine adaptations that are hypothesized to be critical not only for healthy offspring neurodevelopment but also for preserving maternal mental health1,2. At the level of the maternal hypothalamic pituitary adrenal (HPA) axis, adaptions in both circadian and stress-induced levels of glucocorticoid release are observed, including a more flattened rhythm of diurnal HPA axis activity and dampened HPA axis response to acute stressors3,4,5. Given that enhanced HPA axis activity is reported in a subset of women with postpartum affective dysregulation, including increased levels of circulating glucocorticoids and inhibited negative feedback6,7,8, exposure to stressors that result in increased postpartum stress reactivity and prevent maternal HPA axis adaptions are thought to increase susceptibility to neuropsychiatric disorders.
To elucidate the effects of stress on affective dysregulation in mothers and infants, several rodent models of stress in the peripartum period have been generated. A majority of these models are characterized by the application of physical stressors that result in homeostatic challenges and alterations in dam physiological status9, such as chronic restraint stress10 and swim stress during gestation11, or postpartum shock exposure12. Although these paradigms have been shown to result in the emergence of postpartum depressive-like behaviors and alterations in maternal care10,11,12, they have been limited by their inability to accurately capture the psychosocial nature of stressors commonly experienced by human mothers. This becomes particularly important when attempting to reveal the neuroendocrine consequences of chronic stress in the peripartum period, given that processing of different types of stressors is thought to be mediated by varying neural networks orchestrating HPA axis activation9.
In order to overcome this limitation, several groups have designed stress paradigms employing psychosocial insults or a combination of physical and psychosocial stressors. The maternal separation model, where dams are separated from her pups for several hours per day during the postpartum period13,14, and the chronic social stress model, where the dams are exposed to a male intruder in the presence of their litters15,16, have been able to reproduce the emergence of abnormalities in maternal care and depressive-like phenotypes associated with physical stress paradigms. The chronic ultramild stress paradigm, where pregnant female mice are exposed to a variety of psychosocial insults, including cage tilt and overnight illumination, as well as substantial physiological insults, such as restraint stress and food restriction, has further revealed exposure to a mixed nature of stressors results in abnormalities in maternal behavior, including impairments in maternal aggression, as well as dysregulation in the circadian activity of the HPA axis17,18. Consistent with these results, an alternating restraint stress and overcrowding model during gestation results in elevations in postpartum maternal circadian corticosterone levels as well as alterations in maternal care, although no differences are observed in HPA axis re-activity following postpartum exposure to novel acute insults1.
An expansion of this work, generating a gestational stress paradigm that employs multiple psychosocial insults presented in an unpredictable fashion and minimizes the use of physiological stressors. Studies have previously shown this chronic psychosocial stress paradigm (CGS) results in the development of maternal HPA axis dysfunction, including enhanced stress reactivity in the early postpartum period19. These changes are associated with abnormalities in maternal behavior, including alterations in the quality of maternal care received by pups, and the emergence of anhedonic and anxiety-like behaviors19, features consistent with perinatal mood and anxiety disorders20,21. Furthermore, offspring weight gain reduces during the postnatal period following in-utero exposure to CGS19, suggesting CGS may have persistent negative programming effects in future generations.
The goal in developing the CGS paradigm was to primarily utilize clinically relevant stressors, which accurately capture the type, intensity, and frequency of insults often associated with neuroendocrine dysregulation and the development of perinatal mood and anxiety disorders. Here, the study provides a detailed protocol of how to subject pregnant female mice to CGS, as well as downstream assessments that can be used to test the validity of the model.

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			<td>Animal lancet</td>
			<td>Braintree Scientific Inc.</td>
			<td>GR4MM</td>
			<td></td>
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		<tr>
			<td>Blunt end probe</td>
			<td>Fine Science Tools</td>
			<td>10088-15</td>
			<td>Used to check for copulatory plugs</td>
		</tr>
		<tr>
			<td>Bottles for SPT</td>
			<td>Braintree Scientific Inc.</td>
			<td>WTRBTL S-BL</td>
			<td>100 mL glass water bottle with stopper and sipper ball point tube, graduted by 1 mL.</td>
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		<tr>
			<td>Conical tubes (50 mL)</td>
			<td>Corning Inc.</td>
			<td>352098</td>
			<td>Used for restraining mice to measure HPA axis response to acute stress. Make sure conical tube has small opening at the end for ventilation.</td>
		</tr>
		<tr>
			<td>Legos</td>
			<td>Amazon</td>
			<td>-</td>
			<td></td>
		</tr>
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			<td>Marbles</td>
			<td>Amazon</td>
			<td>-</td>
			<td></td>
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		<tr>
			<td>Mouse Corticosterone ELISA kit</td>
			<td>Biovendor</td>
			<td>RTC002R</td>
			<td></td>
		</tr>
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			<td>Mouse EZM</td>
			<td>TSE Systems</td>
			<td>-</td>
			<td></td>
		</tr>
		<tr>
			<td>Reciprocal laboratory shaker</td>
			<td>Labnet international</td>
			<td>S2030-RC-B</td>
			<td></td>
		</tr>
		<tr>
			<td>Serum separator tubes</td>
			<td>Becton Dickinson</td>
			<td>365967</td>
			<td></td>
		</tr>
		<tr>
			<td>Static cage- bottom</td>
			<td>Alternative Design Manufacturing and Supply Inc.</td>
			<td>RC71D-PC</td>
			<td></td>
		</tr>
		<tr>
			<td>Static cage - filtered ventilated tops</td>
			<td>Alternative Design Manufacturing and Supply Inc.</td>
			<td>FT71H-PC</td>
			<td></td>
		</tr>
	</tbody>
</table>

using a murine model of psychosocial stress in pregnancy as a translationally relevant paradigm for psychiatric disorders in mothers and infants

The peripartum period is considered a sensitive period where adverse maternal exposures can result in long-term negative consequences for both mother and offspring, including the development of neuropsychiatric disorders. Risk factors linked to the emergence of affective dysregulation in the maternal-infant dyad have been extensively studied. Exposure to psychosocial stress during pregnancy has consistently emerged as one of the strongest predictors. Several rodent models have been created to explore this association; however, these models rely on the use of physical stressors or a limited number of psychosocial stressors presented in a repetitive fashion, which do not accurately capture the type, intensity, and frequency of stressors experienced by women. To overcome these limitations, a chronic psychosocial stress (CGS) paradigm was generated that employs various psychosocial insults of different intensity presented in an unpredictable fashion. The manuscript describes this novel CGS paradigm where pregnant female mice, from gestational day 6.5 to 17.5, are exposed to various stressors during the day and overnight. Day stressors, two per day separated by a 2 h break, range from exposure to foreign objects or predator odor to frequent changes in bedding, removal of bedding, and cage tilting. Overnight stressors include continuous light exposure, changing cage mates, or wetting bedding. We have previously shown that exposure to CGS results in the development of maternal neuroendocrine and behavioral abnormalities, including increased stress reactivity, the emergence of fragmented maternal care patterns, anhedonia, and anxiety-related behaviors, core features of women suffering from perinatal mood and anxiety disorders. This CGS model, therefore, becomes a unique tool that can be used to elucidate molecular defects underlying maternal affective dysregulation, as well as trans-placental mechanisms that impact fetal neurodevelopment and result in negative long-term behavioral consequences in the offspring.

Exposing the pregnant female mice to CGS results in changes in chronic stress-relevant parameters, including a reduction in body weight gain during pregnancy (Figure 2A) and increased adrenal gland weights in the early postpartum period (Figure 2B)19. Importantly, exposure to CGS results in postpartum abnormalities in maternal neuroendocrine function. CGS dams exhibit a hyperactive HPA axis as evidenced by the increased serum corticostero...

Watch this Scientific Journal Video about Using a Murine Model of Psychosocial Stress in Pregnancy as a Translationally Relevant Paradigm for Psychiatric Disorders in Mothers and Infants at JoVE.com

Using a Murine Model of Psychosocial Stress in Pregnancy as a Translationally Relevant Paradigm for Psychiatric Disorders in Mothers and Infants

The chronic psychosocial stress (CGS) paradigm employs clinically relevant stressors during pregnancy in mice to model psychiatric disorders of mothers and infants. Here, we provide a step-by-step procedure of applying the CGS paradigm and downstream assessments to validate this model.

The peripartum period is considered a sensitive period where adverse maternal exposures can result in long-term negative consequences for both mother and ...

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2.9K Views.  Cincinnati Children’s Hospital Medical Center. The chronic psychosocial stress (CGS) paradigm employs clinically relevant stressors during pregnancy in mice to model psychiatric disorders of mothers and infants. Here, we provide a step-by-step procedure of applying the CGS paradigm and downstream assessments to validate this model.

Video: Using a Murine Model of Psychosocial Stress in Pregnancy as a Translationally Relevant Paradigm for Psychiatric Disorders in Mothers and Infants

The Resident-intruder Paradigm: A Standardized Test for Aggression, Violence and Social Stress

This video publication explains in detail the experimental protocol of the resident-intruder paradigm in rats. This test is a standardized method to measure offensive aggression and defensive behavior in a semi natural setting. The most important behavioral elements performed by the resident and the intruder are demonstrated in the video and illustrated using artistic drawings. The use of the resident intruder paradigm for acute and chronic social stress experiments is explained as well. Finally, some brief tests and criteria are presented to distinguish aggression from its more violent and pathological forms.

This video shows the resident-intruder paradigm in rats. This test is a standardized method to measure offensive aggression, defensive behavior and violence in a semi-natural setting. The use of the paradigm for social stress experiments is explained as well.

This video publication explains in detail the experimental protocol of the resident-intruder paradigm in rats. This test is a standardized method to ...

P50 Sensory Gating in Infants

Attentional deficits are common in a variety of neuropsychiatric disorders including attention deficit-hyperactivity disorder, autism, bipolar mood disorder, and schizophrenia. There has been increasing interest in the neurodevelopmental components of these attentional deficits; neurodevelopmental meaning that while the deficits become clinically prominent in childhood or adulthood, the deficits are the results of problems in brain development that begin in infancy or even prenatally. Despite this interest, there are few methods for assessing attention very early in infancy. This report focuses on one method, infant auditory P50 sensory gating.
Attention has several components. One of the earliest components of attention, termed sensory gating, allows the brain to tune out repetitive, noninformative sensory information. Auditory P50 sensory gating refers to one task designed to measure sensory gating using changes in EEG. When identical auditory stimuli are presented 500 ms apart, the evoked response (change in the EEG associated with the processing of the click) to the second stimulus is generally reduced relative to the response to the first stimulus (i.e. the response is &#34;gated&#34;). When response to the second stimulus is not reduced, this is considered a poor sensory gating, is reflective of impaired cerebral inhibition, and is correlated with attentional deficits.
Because the auditory P50 sensory gating task is passive, it is of potential utility in the study of young infants and may provide a window into the developmental time course of attentional deficits in a variety of neuropsychiatric disorders. The goal of this presentation is to describe the methodology for assessing infant auditory P50 sensory gating, a methodology adapted from those used in studies of adult populations.

Methods to record auditory P50 sensory gating, a physiological marker of cerebral inhibition which reflects early stages of attention, are described.

Attentional deficits are common in a variety of neuropsychiatric disorders including attention deficit-hyperactivity disorder, autism, bipolar mood ...

Using Chronic Social Stress to Model Postpartum Depression in Lactating Rodents

Exposure to chronic stress is a reliable predictor of depressive disorders, and social stress is a common ethologically relevant stressor in both animals and humans. However, many animal models of depression were developed in males and are not applicable or effective in studies of postpartum females. Recent studies have reported significant effects of chronic social stress during lactation, an ethologically relevant and effective stressor, on maternal behavior, growth, and behavioral neuroendocrinology. This manuscript will describe this chronic social stress paradigm using repeated exposure of a lactating dam to a novel male intruder, and the assessment of the behavioral, physiological, and neuroendocrine effects of this model. Chronic social stress (CSS) is a valuable model for studying the effects of stress on the behavior and physiology of the dam as well as her offspring and future generations. The exposure of pups to CSS can also be used as an early life stress that has long term effects on behavior, physiology, and neuroendocrinology.

This article describes the use of chronic resident intruder social stress as an ethologically relevant paradigm to model postpartum depression and anxiety in lactating rodents.

Exposure to chronic stress is a reliable predictor of depressive disorders, and social stress is a common ethologically relevant stressor in both animals ...

The Crossmodal Congruency Task as a Means to Obtain an Objective Behavioral Measure in the Rubber Hand Illusion Paradigm

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden hand is touched. If the viewed and felt touches are given at the same time then this is sufficient to induce the compelling experience that the rubber hand is one's own hand. The RHI can be used to investigate exactly how the brain constructs distinct body representations for one's own body. Such representations are crucial for successful interactions with the external world. To obtain a subjective measure of the RHI, researchers typically ask participants to rate statements such as "I felt as if the rubber hand were my hand". Here we demonstrate how the crossmodal congruency task can be used to obtain an objective behavioral measure within this paradigm.
The variant of the crossmodal congruency task we employ involves the presentation of tactile targets and visual distractors. Targets and distractors are spatially congruent (i.e. same finger) on some trials and incongruent (i.e. different finger) on others. The difference in performance between incongruent and congruent trials - the crossmodal congruency effect (CCE) - indexes multisensory interactions. Importantly, the CCE is modulated both by viewing a hand as well as the synchrony of viewed and felt touch which are both crucial factors for the RHI.
The use of the crossmodal congruency task within the RHI paradigm has several advantages. It is a simple behavioral measure which can be repeated many times and which can be obtained during the illusion while participants view the artificial hand. Furthermore, this measure is not susceptible to observer and experimenter biases. The combination of the RHI paradigm with the crossmodal congruency task allows in particular for the investigation of multisensory processes which are critical for modulations of body representations as in the RHI.

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden ...

Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach

The main goal of this study was to assess the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognitive functions across the lifespan in a sample of 378 healthy subjects (age range 18-89 years). Consistent with previous findings we found an age-related cognitive decline across a wide range of neuropsychological domains (memory, attention, executive functions), thereby proving the usability of our tablet-based application. Regardless of prior computer experience, subjects of all age groups were able to perform the tasks without instruction or feedback from an experimenter. Increased motivation and compliance proved to be beneficial for task performance, thereby potentially increasing the validity of the results. Our promising findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.

We tested the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognition. Results show an age-related cognitive decline, thereby proving the usability of our application. Findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.

The main goal of this study was to assess the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on ...

Vagus Nerve Stimulation as a Tool to Induce Plasticity in Pathways Relevant for Extinction Learning

Extinction describes the process of attenuating behavioral responses to neutral stimuli when they no longer provide the reinforcement that has been maintaining the behavior. There is close correspondence between fear and human anxiety, and therefore studies of extinction learning might provide insight into the biological nature of anxiety-related disorders such as post-traumatic stress disorder, and they might help to develop strategies to treat them. Preclinical research aims to aid extinction learning and to induce targeted plasticity in extinction circuits to consolidate the newly formed memory. Vagus nerve stimulation (VNS) is a powerful approach that provides tight temporal and circuit-specific release of neurotransmitters, resulting in modulation of neuronal networks engaged in an ongoing task. VNS enhances memory consolidation in both rats and humans, and pairing VNS with exposure to conditioned cues enhances the consolidation of extinction learning in rats. Here, we provide a detailed protocol for the preparation of custom-made parts and the surgical procedures required for VNS in rats. Using this protocol we show how VNS can facilitate the extinction of conditioned fear responses in an auditory fear conditioning task. In addition, we provide evidence that VNS modulates synaptic plasticity in the pathway between the infralimbic (IL) medial prefrontal cortex and the basolateral complex of the amygdala (BLA), which is involved in the expression and modulation of extinction memory.

Vagus nerve stimulation (VNS) has emerged as a tool to induce targeted synaptic plasticity in the forebrain to modify a range of behaviors. This protocol describes how to implement VNS to facilitate the consolidation of fear extinction memory.

Extinction describes the process of attenuating behavioral responses to neutral stimuli when they no longer provide the reinforcement that has been ...

The Social Dimension of Stress: Experimental Manipulations of Social Support and Social Identity in the Trier Social Stress Test

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)&#8212;a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks.

Previous research on the social dimension of stress has focused on two important variables: social identity and social support. This protocol introduces an effective experimental manipulation of these two social variables and describes their implementation in a standard stress induction paradigm (Trier Social Stress Test).

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations ...

Ultrasound Images of the Tongue: A Tutorial for Assessment and Remediation of Speech Sound Errors

Diagnostic ultrasound imaging has been a common tool in medical practice for several decades. It provides a safe and effective method for imaging structures internal to the body. There has been a recent increase in the use of ultrasound technology to visualize the shape and movements of the tongue during speech, both in typical speakers and in clinical populations. Ultrasound imaging of speech has greatly expanded our understanding of how sounds articulated with the tongue (lingual sounds) are produced. Such information can be particularly valuable for speech-language pathologists. Among other advantages, ultrasound images can be used during speech therapy to provide (1) illustrative models of typical (i.e.&#160;&#34;correct&#34;) tongue configurations for speech sounds, and (2) a source of insight into the articulatory nature of deviant productions. The images can also be used as an additional source of feedback for clinical populations learning to distinguish their better productions from their incorrect productions, en route to establishing more effective articulatory habits.
Ultrasound feedback is increasingly used by scientists and clinicians as both the expertise of the users increases and as the expense of the equipment declines. In this tutorial, procedures are presented for collecting ultrasound images of the tongue in a clinical context. We illustrate these procedures in an extended example featuring one common error sound, American English /r/. Images of correct and distorted /r/ are used to demonstrate (1) how to interpret ultrasound images, (2) how to assess tongue shape during production of speech sounds, (3), how to categorize tongue shape errors, and (4), how to provide visual feedback to elicit a more appropriate and functional tongue shape. We present a sample protocol for using real-time ultrasound images of the tongue for visual feedback to remediate speech sound errors. Additionally, example data are shown to illustrate outcomes with the procedure.

Ultrasound imaging can be used to display the shape and movements of the tongue in real time during speech. The images can be used to determine the nature of speech sound errors. Visual feedback of the tongue can be used to facilitate improvements in speech sound production in clinical populations.

Diagnostic ultrasound imaging has been a common tool in medical practice for several decades. It provides a safe and effective method for imaging ...

Reinstatement of Drug-seeking in Mice Using the Conditioned Place Preference Paradigm

The present protocol describes the Conditioned Place Preference (CPP) as a model of relapse in drug addiction. In this model, animals are first trained to acquire a conditioned place preference in a drug-paired compartment, and after the post-conditioning test, they perform several sessions to extinguish the established preference. The CPP permits the evaluation of the conditioned rewarding effects of drugs related to environmental cues. Then, the extinguished CPP can be robustly reinstated by the non-contingent administration of a priming dose of the drug, and by exposure to stressful stimuli. Both methods will be explained here. When the animal reinitiates the behavioral response, a reinstatement of the conditioned reward is considered to have taken place.
The main advantages of this protocol are that it is non-invasive, inexpensive, and simple with good validity criteria. In addition, it allows the study of different environmental manipulations, such as stress or diet, which can modulate relapse into drug seeking behaviors. However, one limitation is that if the researcher aims to explore the motivation and primary reinforcing effects of the drug, it should be complemented with self-administration procedures, as they involve operant responses of animals.

This protocol describes the Conditioned Place Preference (CPP) as a model of relapse. This procedure permits the measurement of relapse in laboratory animals, considering the impact of drug-associated environmental cues as craving and relapse in abstaining addicts is currently the focus of drug-abuse treatment programs.

The present protocol describes the Conditioned Place Preference (CPP) as a model of relapse in drug addiction. In this model, animals are first trained to ...

A High-performance Liquid Chromatography Measurement of Kynurenine and Kynurenic Acid: Relating Biochemistry to Cognition and Sleep in Rats

The kynurenine pathway (KP) of tryptophan degradation has been implicated in psychiatric disorders. Specifically, the astrocyte-derived metabolite kynurenic acid (KYNA), an antagonist at both N-methyl-d-aspartate (NMDA) and &#945;7 nicotinic acetylcholine (&#945;7nACh) receptors, has been implicated in cognitive processes in health and disease. As KYNA levels are elevated in the brains of patients with schizophrenia, a malfunction at the glutamatergic and cholinergic receptors is believed to be causally related to cognitive dysfunction, a core domain of the psychopathology of the illness. KYNA may play a pathophysiologically significant role in individuals with schizophrenia. It is possible to elevate endogenous KYNA in the rodent brain by treating animals with the direct bioprecursor kynurenine, and preclinical studies in rats have demonstrated that acute elevations in KYNA may impact their learning and memory processes. The current protocol describes this experimental approach in detail and combines a) a biochemical analysis of blood kynurenine levels and brain KYNA formation (using high-performance liquid chromatography), b) behavioral testing to probe the hippocampal-dependent contextual memory (passive avoidance paradigm), and c) an assessment of sleep-wake behavior [telemetric recordings combining electroencephalogram (EEG) and electromyogram (EMG) signals] in rats. Taken together, a relationship between elevated KYNA, sleep, and cognition is studied, and this protocol describes in detail an experimental approach to understanding function outcomes of kynurenine elevation and KYNA formation in vivo in rats. Results obtained through variations of this protocol will test the hypothesis that the KP and KYNA serve pivotal roles in modulating sleep and cognition in health and disease states.

Alterations in the kynurenine pathway (KP) neuroactive metabolites are implicated in psychiatric illnesses. Investigating the functional outcomes of an altered kynurenine pathway metabolism in vivo in rodents may help elucidate novel therapeutic approaches. The current protocol combines biochemical and behavioral approaches to investigate the impact of an acute kynurenine challenge in rats.