The authors would like to thank Dr. Christina Ginkel (German Center for Neurodegenerative Diseases, DZNE), Dr. Michaela M&#246;hring (DZNE) and Dr. Robert Stark (DZNE) for assistance in animal breeding and animal health care. This work was financially supported by the Federal Institute for Drugs and Medical Devices (Bundesinstitut f&#252;r Arzneimittel und Medizinprodukte, BfArM) Bonn, Germany.

The authors have nothing to disclose.

Implantable EEG radiotelemetry is of central relevance as it is a non-restraining technique allowing experimental animals to perform their full repertoire of behavior1,3. This is of major interest as the telemetric approach enables not only spontaneous EEG recordings but also recordings under cognitive tasks and circadian analytical setups, such as T-maze, radial maze, water maze, sleep deprivation tasks or whenever an EEG recording is necessary or helpful during complex cognitive or motor activity.
<p cla...

Radiotelemetry is a most valuable methodological approach for measuring a variety of behavioral and physiological parameters in conscious, unrestrained animals of various sizes, particularly in the context of EEG, ECG, EMG, blood pressure, body core temperature or activity measurements 1-7. Theoretically, any species can be analyzed using implantable EEG radiotelemetry from laboratory rodents such as mice and rats to cats, dogs, pigs and primates 3,8. Even fish, reptiles and amphibians are subject to radiotelemetric investigation 9. Over the last two decades, implantable EEG radiotelemetry has proven to be valuable in the characterization of various transgenic animal models of human diseases, such as epilepsies, sleep disorders, neurodegenerative and neuropsychiatric disorders 7,10-12. In the past, numerous methodological approaches collecting physiological data including biopotentials from mice and rats have been described. Worn in jacket recorder systems, physical restraint methods, non-implanted radiotransmitters and tethered systems have received the main attention in the past 13,14. Nowadays, various systems for radiotelemetric implantation are commercially available. However, a literature screen also revealed 29 publications that describe the development of self-made radiotelemetric systems 15-40. Whereas home-made systems are likely to be less expensive and more user adapted, commercially available systems are straight forward, relatively easy to install and can be setup quickly.
Implantable EEG radiotelemetry has a number of advantages compared to competing techniques such as physical restraint methods, worn in jacket systems or tethered approaches. The latter are restraining by definition, i.e., the animal is unable to move or its normal behavior is impaired. It might even be necessary to anesthetize the animal for acquisition of reliable data. Modern tethered systems however are likely to be less restraining, but this needs to be scientifically validated. Radiotelemetry on the other hand allows animals to exhibit their full repertoire of behavior without spatiotemporal restrictions and thus, is thought to be superior to restraining approaches and be more predictive of the results that could be acquired in humans 1,3. It is known for quite a while that restraining approaches can dramatically alter fundamental physiological parameters, e.g., food intake, body core temperature, blood pressure and heart rate and physical activity for example 3. Tethered systems represent one still widely used classical restraining approach 13,14. The electrodes which are either epidural or deep electrodes are generally connected to a miniature socket which is anchored to the skull. The socket itself is exposed for attachment of a cable that allows relatively free movement of the animal. Although nowadays tethered systems have become extremely filigree and highly flexible, one of its major disadvantages is, that it is still semi-restraining. Besides, there might be a risk of infection at the electrode implantation site as the animals tend to manipulate any external devices originating from their body (head). Although wireless radiotelemetry technology in various species has already been described in the late 60s and has thus existed for decades, it has only recently become affordable, reliable, and relatively easy-to-use 10,41,42, particularly in small laboratory rodents such as mice and rats. Small, miniature implantable EEG transmitters are now commercially available and can be implanted in mice greater than 20 g (~10 weeks). Thus, the electrophysiological characterization of transgenic mouse models in particular has become a predominant field of application of implantable EEG radiotelemetry these days. Animal size is no longer an absolute experimental restriction whereas the life-span of the transmitters&#39; battery indeed is. Despite its limited life-time, implantable transmitter systems are capable of minimizing most disadvantages related to potential recording-associated stress by restraining systems. Rodents can present their complete armamentarium of physiological behavior including resting, locomotor activity (exploration) and sleep (REM, slow-wave sleep) 43,44. Importantly, implantable radiotelemetry can strongly reduce animal use 3. Currently, there is an intense discussion on how to limit the number of experimental animals in science and reduce their suffering. Clearly, animal experimentation and animal models of human and animal diseases are essential for our understanding of the bottom-line pathophysiology and subsequent progress in therapy. Furthermore, animal experiments are critical in drug research and development. They do substantially contribute to preclinical/toxicological studies in drug licensing thus committing to both human and animal care. It&#39;s noteworthy, that currently no alternatives are yet available to animal research to understand the complex pathophysiological mechanisms which would be otherwise impossible to be elicited. At the same time, the 3R, i.e., replacement, reduction and refinement strategy in the EU and the USA strongly encourages research into complementary and alternative methods. Radiotelemetry is an important example of a successful 3R strategy as it can reduce the number of experimental animals and their suffering compared to other techniques.
Here we provide a detailed and contiguous step-by-step approach to perform a subcutaneous pouch implantation of a radiofrequency transmitter in both mice and rats. This first sequence is followed by a description of stereotaxic epidural and deep intracerebral EEG electrode positioning. Special attention is paid to housing conditions, anesthesia, peri- and postoperative pain management and possible anti-infective treatment. The focus is on the computerized 3D stereotaxic approach to reliably target epidural and deep intracerebral structures. We also comment on frequent experimental pitfalls in EEG electrode implantation and strategies for reduction of trauma and optimization of pain management during postoperative recovery. Finally, examples of surface and deep EEG recordings are presented.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Carprofen (Rimadyl VET - InjektionA2:D43sl&#246;sung)</td>
			<td>Pfizer</td>
			<td>PZN 0110208</td>
			<td>20 ml</td>
		</tr>
		<tr>
			<td>binocular surgical magnification microscope&#160;</td>
			<td>Zeiss Stemi 2000</td>
			<td>0000001003877, 4355400000000, 0000001063306, 4170530000000, 4170959255000, 4551820000000, 4170959040000, 4170959050000</td>
			<td></td>
		</tr>
		<tr>
			<td>bulldog serrefine</td>
			<td>F.S.T.</td>
			<td>18051-28</td>
			<td>28mm</td>
		</tr>
		<tr>
			<td>cages (Macrolon)</td>
			<td>Techniplast</td>
			<td>1264C, 1290D</td>
			<td></td>
		</tr>
		<tr>
			<td>cold light source</td>
			<td>Schott KL2500 LCD</td>
			<td>9.705&#160;202</td>
			<td>ordered at Th.Geyer</td>
		</tr>
		<tr>
			<td>cotton tip applicators (sterile)</td>
			<td>Carl Roth&#160;</td>
			<td>EH12.1</td>
			<td></td>
		</tr>
		<tr>
			<td>Dexpanthenole (Bepanthen Wund- und Heilsalbe)</td>
			<td>Bayer</td>
			<td>PZN: 1578818</td>
			<td></td>
		</tr>
		<tr>
			<td>drapes (sterile)</td>
			<td>Hartmann</td>
			<td>PZN 0366787</td>
			<td></td>
		</tr>
		<tr>
			<td>70% ethanol</td>
			<td>Carl Roth&#160;</td>
			<td>9065.5</td>
			<td></td>
		</tr>
		<tr>
			<td>0.3% / 3% hydrogene peroxide solution</td>
			<td>Sigma</td>
			<td>95321</td>
			<td>30% stock solution&#160;</td>
		</tr>
		<tr>
			<td>gloves (sterile)</td>
			<td>Unigloves</td>
			<td>1570</td>
			<td></td>
		</tr>
		<tr>
			<td>dental glas ionomer cement</td>
			<td>KentDental /NORDENTA</td>
			<td>957 321</td>
			<td></td>
		</tr>
		<tr>
			<td>2% glutaraldehyde solution</td>
			<td>Sigma</td>
			<td>G6257</td>
			<td></td>
		</tr>
		<tr>
			<td>Graefe Forceps-curved, serrated</td>
			<td>F.S.T.</td>
			<td>11052-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Halsey Micro Needle Holder-Tungsten Carbide</td>
			<td>F.S.T.</td>
			<td>12500-12</td>
			<td>12.5 cm</td>
		</tr>
		<tr>
			<td>heat-based surgical instrument sterilizer</td>
			<td>F.S.T.</td>
			<td>18000-50</td>
			<td></td>
		</tr>
		<tr>
			<td>heating pad</td>
			<td>AEG HK5510</td>
			<td>520010</td>
			<td>ordered at myToolStore</td>
		</tr>
		<tr>
			<td>high-speed dental drill</td>
			<td>Adeor</td>
			<td>SI-1708</td>
			<td></td>
		</tr>
		<tr>
			<td>Iris scissors extra thin&#160;</td>
			<td>F.S.T.</td>
			<td>14058-09</td>
			<td>9 cm</td>
		</tr>
		<tr>
			<td>Inhalation narcotic system (isoflurane)</td>
			<td>Harvard Apparatus GmbH</td>
			<td>34-1352, 10-1340, 34-0422, 34-1041, 34-0401, 34-1067, 72-3044, 34-0426, 34-0387, 34-0415, 69-0230</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Baxter 250 ml</td>
			<td>PZN 6497131</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>Pfizer</td>
			<td>PZN 07506004</td>
			<td></td>
		</tr>
		<tr>
			<td>lactated Ringer&#8217;s solution (sterile)</td>
			<td>Braun</td>
			<td>L7502</td>
			<td></td>
		</tr>
		<tr>
			<td>Lexar-Baby Scissors-straight, 10 cm</td>
			<td>F.S.T.</td>
			<td>14078-10</td>
			<td>10 cm</td>
		</tr>
		<tr>
			<td>Nissl staining solution</td>
			<td>Armin Baack</td>
			<td>BAA31712159</td>
			<td></td>
		</tr>
		<tr>
			<td>non-absorbable suture material 5-0/6-0 (sterile)</td>
			<td>SABANA (Sabafil)</td>
			<td>N-63123-45</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td>Covidien (Sofsilk)</td>
			<td>S1172, S1173</td>
			<td></td>
		</tr>
		<tr>
			<td>Halsey Needle Holder</td>
			<td>F.S.T.</td>
			<td>12001-13</td>
			<td>13 cm</td>
		</tr>
		<tr>
			<td>pads (sterile)</td>
			<td>ReWa Krankenhausbedarf</td>
			<td>2003/01</td>
			<td></td>
		</tr>
		<tr>
			<td>0.9% saline (NaCl, sterile)</td>
			<td>Braun</td>
			<td>PZN:8609255</td>
			<td></td>
		</tr>
		<tr>
			<td>scalpel blades with handle (sterile)</td>
			<td>propraxis</td>
			<td>2029/10</td>
			<td></td>
		</tr>
		<tr>
			<td>Standard Pattern Forceps</td>
			<td>F.S.T.</td>
			<td>11000-12, 11000-14</td>
			<td>12 cm and 14.5 cm length</td>
		</tr>
		<tr>
			<td>Steel and tungsten electrodes parylene coated&#160;</td>
			<td>FHC Inc., USA)</td>
			<td>UEWLGESEANND</td>
			<td></td>
		</tr>
		<tr>
			<td>stereotaxic frame</td>
			<td>Neurostar</td>
			<td>51730M</td>
			<td>ordered at Stoelting</td>
		</tr>
		<tr>
			<td>(Stereo Drive-New Motorized Stereotaxic)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>tapes (sterile)</td>
			<td>BSN medical GmbH &#38; Co. KG</td>
			<td>626225</td>
			<td></td>
		</tr>
		<tr>
			<td>TA10ETA-F20&#160;</td>
			<td>DSI</td>
			<td>270-0042-001X</td>
			<td>Radiofrequency transmitter 3.9 g,&#160; 
			3.9 g, 1.9 cc, input voltage range &#177; 2.5 mV, 
			channel bandwidth (B) 1-200 Hz,&#160; 
			nominal sampling rate (f) 1000 Hz (f = 5B) 
			temperature operating range 34-41 &#176;C 
			warranted battery life 4 months</td>
		</tr>
		<tr>
			<td>TL11M2-F20EET&#160;</td>
			<td>DSI</td>
			<td>270-0124-001X</td>
			<td>Radiofrequency transmitter&#160; 
			3.9 g, 1.9 cc, input voltage range &#177; 1.25 mV, 
			channel bandwidth (B) 1-50 Hz,&#160; 
			nominal sampling rate (f) 250 Hz (f = 5B) 
			temperature operating range 34-41 &#176;C 
			warranted battery life 1.5 months</td>
		</tr>
		<tr>
			<td>Tissue Forceps- 1x2 Teeth 12 cm</td>
			<td>F.S.T.</td>
			<td>11021-12</td>
			<td>12 cm length</td>
		</tr>
		<tr>
			<td>Tungsten carbide iris scissors</td>
			<td>F.S.T.</td>
			<td>14558-11</td>
			<td>11.5 cm</td>
		</tr>
		<tr>
			<td>Vibroslicer 5000 MZ</td>
			<td>Electron Microscopy Sciences</td>
			<td>5000-005</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylazine (Rompun)</td>
			<td>Bayer</td>
			<td>PZN: 1320422</td>
			<td></td>
		</tr>
	</tbody>
</table>

non-restraining eeg radiotelemetry: epidural and deep intracerebral stereotaxic eeg electrode placement

Implantable EEG radiotelemetry is of central relevance in the neurological characterization of transgenic mouse models of neuropsychiatric and neurodegenerative diseases as well as epilepsies. This powerful technique does not only provide valuable insights into the underlying pathophysiological mechanisms, i.e., the etiopathogenesis of CNS related diseases, it also facilitates the development of new translational, i.e., therapeutic approaches. Whereas competing techniques that make use of recorder systems used in jackets or tethered systems suffer from their unphysiological restraining to semi-restraining character, radiotelemetric EEG recordings overcome these disadvantages. Technically, implantable EEG radiotelemetry allows for precise and highly sensitive measurement of epidural and deep, intracerebral EEGs under various physiological and pathophysiological conditions. First, we present a detailed protocol of a straight forward, successful, quick and efficient technique for epidural (surface) EEG recordings resulting in high-quality electrocorticograms. Second, we demonstrate how to implant deep, intracerebral EEG electrodes, e.g., in the hippocampus (electrohippocampogram). For both approaches, a computerized 3D stereotaxic electrode implantation system is used. The radiofrequency transmitter itself is implanted into a subcutaneous pouch in both mice and rats. Special attention also has to be paid to pre-, peri- and postoperative treatment of the experimental animals. Preoperative preparation of mice and rats, suitable anesthesia as well as postoperative treatment and pain management are described in detail.

This section illustrates examples obtained from surface and deep, intracerebral EEG recordings. Initially it should be stated that baseline recordings under physiological conditions are mandatory prior to subsequent recordings following e.g., pharmacological treatment. Such baseline recordings may provide valuable information about functional interdependence of brain rhythmicity with different behavioral states or sleep / circadian rhythmicity. Here, we show examples of recorded ...

Watch this Scientific Journal Video about Non-restraining EEG Radiotelemetry: Epidural and Deep Intracerebral Stereotaxic EEG Electrode Placement at JoVE.com

Non-restraining EEG Radiotelemetry: Epidural and Deep Intracerebral Stereotaxic EEG Electrode Placement

Non-restraining EEG radiotelemetry is a valuable methodological approach to record in vivo long-term electroencephalograms from freely moving rodents. This detailed protocol describes stereotaxic epidural and deep intracerebral electrode placement in different brain regions in order to obtain reliable recordings of CNS rhythmicity and CNS related behavioral stages.

Implantable EEG radiotelemetry is of central relevance in the neurological characterization of transgenic mouse models of neuropsychiatric and ...

non-restraining-eeg-radiotelemetry-epidural-deep-intracerebral

Research

JoVE Journal

Neuroscience

18.9K Views.  Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM). Non-restraining EEG radiotelemetry is a valuable methodological approach to record in vivo long-term electroencephalograms from freely moving rodents. This detailed protocol describes stereotaxic epidural and deep intracerebral electrode placement in different brain regions in order to obtain reliable recordings of CNS rhythmicity and CNS related behavioral stages.

Video: Non-restraining EEG Radiotelemetry: Epidural and Deep Intracerebral Stereotaxic EEG Electrode Placement

Functional Mapping with Simultaneous MEG and EEG

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the processing of simple sensory stimuli. We will use somatosensory stimuli to locate the hand somatosensory areas, auditory stimuli to locate the auditory cortices, visual stimuli in four quadrants of the visual field to locate the early visual areas. These type of experiments are used for functional mapping in epileptic and brain tumor patients to locate eloquent cortices. In basic neuroscience similar experimental protocols are used to study the orchestration of cortical activity. The acquisition protocol includes quality assurance procedures, subject preparation for the combined MEG/EEG study, and acquisition of evoked-response data with somatosensory, auditory, and visual stimuli. We also demonstrate analysis of the data using the equivalent current dipole model and cortically-constrained minimum-norm estimates. Anatomical MRI data are employed in the analysis for visualization and for deriving boundaries of tissue boundaries for forward modeling and cortical location and orientation constraints for the minimum-norm estimates.

We use magnetoencephalography (MEG) and electroencephalography (EEG) to map brain areas involved in the processing of simple sensory stimuli.

We use magnetoencephalography (MEG) and electroencephalography (EEG) to locate and determine the temporal evolution in brain areas involved in the ...

High-density EEG Recordings of the Freely Moving Mice using Polyimide-based Microelectrode

Electroencephalogram (EEG) indicates the averaged electrical activity of the neuronal populations on a large-scale level. It is widely utilized as a noninvasive brain monitoring tool in cognitive neuroscience as well as a diagnostic tool for epilepsy and sleep disorders in neurology. However, the underlying mechanism of EEG rhythm generation is still under the veil. Recently introduced polyimide-based microelectrode (PBM-array) for high resolution mouse EEG1 is one of the trials to answer the neurophysiological questions on EEG signals based on a rich genetic resource that the mouse model contains for the analysis of complex EEG generation process. This application of nanofabricated PBM-array to mouse skull is an efficient tool for collecting large-scale brain activity of transgenic mice and accommodates to identify the neural correlates to certain EEG rhythms in conjunction with behavior. However its ultra-thin thickness and bifurcated structure cause a trouble in handling and implantation of PBM-array. In the presented video, the preparation and surgery steps for the implantation of PBM-array on a mouse skull are described step by step. Handling and surgery tips to help researchers succeed in implantation are also provided.

In this article, we described the surgery procedure and handling tips for implantation of ultra-thin polyimide-based microelectrode array (PBM-array) on the mouse skull for acquisition of high-density encephalography (EEG) in a mouse model.

Electroencephalogram (EEG) indicates the averaged electrical activity of the neuronal populations on a large-scale level. It is widely utilized as a ...

Preterm EEG: A Multimodal Neurophysiological Protocol

Since its introduction in early 1950s, electroencephalography (EEG) has been widely used in the neonatal intensive care units (NICU) for assessment and monitoring of brain function in preterm and term babies. Most common indications are the diagnosis of epileptic seizures, assessment of brain maturity, and recovery from hypoxic-ischemic events. EEG recording techniques and the understanding of neonatal EEG signals have dramatically improved, but these advances have been slow to penetrate through the clinical traditions. The aim of this presentation is to bring theory and practice of advanced EEG recording available for neonatal units. 
In the theoretical part, we will present animations to illustrate how a preterm brain gives rise to spontaneous and evoked EEG activities, both of which are unique to this developmental phase, as well as crucial for a proper brain maturation. Recent animal work has shown that the structural brain development is clearly reflected in early EEG activity. Most important structures in this regard are the growing long range connections and the transient cortical structure, subplate. Sensory stimuli in a preterm baby will generate responses that are seen at a single trial level, and they have underpinnings in the subplate-cortex interaction. This brings neonatal EEG readily into a multimodal study, where EEG is not only recording cortical function, but it also tests subplate function via different sensory modalities. Finally, introduction of clinically suitable dense array EEG caps, as well as amplifiers capable of recording low frequencies, have disclosed multitude of brain activities that have as yet been overlooked.
In the practical part of this video, we show how a multimodal, dense array EEG study is performed in neonatal intensive care unit from a preterm baby in the incubator. The video demonstrates preparation of the baby and incubator, application of the EEG cap, and performance of the sensory stimulations.

This video explains the background theory of the neonatal EEG activity and the sensory responses, followed by a live demonstration of their recording in neonatal intensive care unit.

Since its introduction in early 1950s, electroencephalography (EEG) has been widely used in the neonatal intensive care units (NICU) for assessment and ...

Applications of EEG Neuroimaging Data: Event-related Potentials, Spectral Power, and Multiscale Entropy

When considering human neuroimaging data, an appreciation of signal variability represents a fundamental innovation in the way we think about brain signal. Typically, researchers represent the brain's response as the mean across repeated experimental trials and disregard signal fluctuations over time as "noise". However, it is becoming clear that brain signal variability conveys meaningful functional information about neural network dynamics. This article describes the novel method of multiscale entropy (MSE) for quantifying brain signal variability. MSE may be particularly informative of neural network dynamics because it shows timescale dependence and sensitivity to linear and nonlinear dynamics in the data.

Neuroimaging researchers typically consider the brain's response as the mean activity across repeated experimental trials and disregard signal variability over time as "noise". However, it is becoming clear that there is signal in that noise. This article describes the novel method of multiscale entropy for quantifying brain signal variability in the time domain.

When considering human neuroimaging data, an appreciation of signal variability represents a fundamental innovation in the way we think about brain ...

Recording EEG in Freely Moving Neonatal Rats Using a Novel Method

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such as epilepsy and neurodegenerative disorders. However, it is technically difficult to obtain EEG recordings in neonates as it requires specialized handling and great care. Here, we present a novel method to record EEG in neonatal rat pups (P8-P15). We designed a simple and reliable electrode using computer pin loci; it can be easily implanted into the skull of a rat pup to record high-quality EEG signals in the normal and epileptic brain. Pups were given an intraperitoneal (i.p.) injection of the neurotoxin kainic acid (KA) to induce epileptic seizures. The surgical implantation performed in this procedure is less expensive than other EEG procedures for neonates. This method allows one to record high-quality and stable EEG signals for more than 1 week. Furthermore, this procedure can also be applied to adult rats and mice to study epilepsy or other neurological disorders.

Here, we introduce a novel technique designed to record electroencephalography (EEG) in freely moving neonatal epileptic pups and describe its procedures, features, and applications. This method allows one to record EEG for more than 1 week.

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such ...

Using Brain Activation (nir-HEG/Q-EEG) and Execution Measures (CPTs) in a ADHD Assessment Protocol

Attention Deficit Hyperactivity Disorder (ADHD) is a problem that impacts academic performance and has serious consequences that result in difficulties in scholastic, social and familial contexts. One of the most common problems in the identification of this disorder relates to the apparent over diagnosis of the disorder due to the absence of global protocols for assessment. The research group of School Learning, Difficulties and Academic Performance (ADIR) from the University of Oviedo, has developed a complete protocol that suggests the existence of certain patterns of cortical activation and executive control for identifying ADHD more objectively. This protocol takes into consideration some of the hypothetical determinants of ADHD, including the relationship between activation of selected areas of the brain, and differences in performance on various aspects of executive functioning such as omissions, commissions or response times, using innovative tools of Continuous Performance Testing (based on Virtual Reality CPT and Traditional CPT) and brain activation measures (two different tools, based on Hemoencephalography- nirHEG; and Quantified Electroencephalography --Q-EEG, respectively). This model of assessment aims to provide an effective assessment of ADHD symptomatology in order to design an accurate intervention and make appropriate recommendations for parents and teachers.

Using Brain Activation nir-HEG/Q-EEG and Execution Measures CPTs in a ADHD Assessment Protocol

This work presents a new protocol for the assessment of Attention Deficit Hyperactivity Disorder (ADHD) by providing a more objective diagnostic procedure for this developmental disorder based on the use of innovative tools. It also analyzes the relationship between activation measures and executive function measures.

Attention Deficit Hyperactivity Disorder (ADHD) is a problem that impacts academic performance and has serious consequences that result in difficulties in ...

Analyzing Neural Activity and Connectivity Using Intracranial EEG Data with SPM Software

Measuring neural activity and connectivity associated with cognitive functions at high spatial and temporal resolutions is an important goal in cognitive neuroscience. Intracranial electroencephalography (EEG) can directly record electrical neural activity and has the unique potential to accomplish this goal. Traditionally, averaging analysis has been applied to analyze intracranial EEG data; however, several new techniques are available for depicting neural activity and intra- and inter-regional connectivity. Here, we introduce two analytical protocols we recently applied to analyze intracranial EEG data using the Statistical Parametric Mapping (SPM) software: time-frequency SPM analysis for neural activity and dynamic causal modeling of induced responses for intra- and inter-regional connectivity. We report our analysis of intracranial EEG data during the observation of faces as representative results. The results revealed that the inferior occipital gyrus (IOG) showed gamma-band activity at very early stages (110 ms) in response to faces, and both the IOG and amygdala showed rapid intra- and inter-regional connectivity using various types of oscillations. These analytical protocols have the potential to identify the neural mechanisms underlying cognitive functions with high spatial and temporal profiles.

We present two analytical protocols that can be used to analyze intracranial electroencephalography data using the Statistical Parametric Mapping (SPM) software: time-frequency statistical parametric mapping analysis for neural activity, and dynamic causal modeling of induced responses for intra- and inter-regional connectivity.

Measuring neural activity and connectivity associated with cognitive functions at high spatial and temporal resolutions is an important goal in cognitive ...

Noninvasive EEG Recordings from Freely Moving Piglets

The method allows the recording of high-quality electroencephalograms (EEGs) from freely moving piglets directly in the pigpen. We use a one-channel telemetric electroencephalography system in combination with standard self-adhesive hydrogel electrodes. The piglets are calmed down without the use of sedatives. After their release into the pigpen, the piglets behave normally&#8212;they drink and sleep in the same cycle as their siblings. Their sleep phases are used for the EEG recordings.

Here, we present a protocol to record telemetric electroencephalograms (EEGs) from freely moving piglets directly in the pigpen without the use of a sedative, making it possible to record typical EEG patterns during non-REM sleep, like spindle bursts.

The method allows the recording of high-quality electroencephalograms (EEGs) from freely moving piglets directly in the pigpen. We use a one-channel ...

Microdialysis of Excitatory Amino Acids During EEG Recordings in Freely Moving Rats

Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain interstitial space with the behavior and/or with the specific outcome of a pathology (e.g., seizures for epilepsy). When studying epilepsy, the microdialysis technique is often combined with short-term or even long-term video-electroencephalography (EEG) monitoring to assess spontaneous seizure frequency, severity, progression and clustering. The combined microdialysis-EEG is based on the use of several methods and instruments. Here, we performed in vivo microdialysis and continuous video-EEG recording to monitor glutamate and aspartate outflow over time, in different phases of the natural history of epilepsy in a rat model. This combined approach allows the pairing of changes in the neurotransmitter release with specific stages of the disease development and progression. The amino acid concentration in the dialysate was determined by liquid chromatography. Here, we describe the methods and outline the principal precautionary measures one should take during in vivo microdialysis-EEG, with particular attention to the stereotaxic surgery, basal and high potassium stimulation during microdialysis, depth electrode EEG recording and high-performance liquid chromatography analysis of aspartate and glutamate in the dialysate. This approach may be adapted to test a variety of drug or disease induced changes of the physiological concentrations of aspartate and glutamate in the brain. Depending on the availability of an appropriate analytical assay, it may be further used to test different soluble molecules when employing EEG recording at the same time.

Here, we describe a method for in vivo microdialysis to analyze aspartate and glutamate release in the ventral hippocampus of epileptic and non-epileptic rats, in combination with EEG recordings. Extracellular concentrations of aspartate and glutamate may be correlated with the different phases of the disease.

Microdialysis is a well-established neuroscience technique that correlates the changes of neurologically active substances diffusing into the brain ...

In Vivo Intracerebral Stereotaxic Injections for Optogenetic Stimulation of Long-Range Inputs in Mouse Brain Slices

Knowledge of cell-type specific synaptic connectivity is a crucial prerequisite for understanding brain-wide neuronal circuits. The functional investigation of long-range connections requires targeted recordings of single neurons combined with the specific stimulation of identified distant inputs. This is often difficult to achieve with conventional and electrical stimulation techniques, because axons from converging upstream brain areas may intermingle in the target region. The stereotaxic targeting of a specific brain region for virus-mediated expression of light-sensitive ion channels allows selective stimulation of axons originating from that region with light. Intracerebral stereotaxic injections can be used in well-delimited structures, such as the anterior thalamic nuclei, in addition to other subcortical or cortical areas throughout the brain.
Described here is a set of techniques for precise stereotaxic injection of viral vectors expressing channelrhodopsin in the mouse brain, followed by photostimulation of axon terminals in the brain slice preparation. These protocols are simple and widely applicable. In combination with whole-cell patch clamp recording from a postsynaptically connected neuron, photostimulation of axons allows the detection of functional synaptic connections, pharmacological characterization, and evaluation of their strength. In addition, biocytin filling of the recorded neuron can be used for post-hoc morphological identification of the postsynaptic neuron.

This protocol describes a set of methods to identify the cell-type specific functional connectivity of long-range inputs from distant brain regions using optogenetic stimulations in ex vivo brain slices.