Amygdala adenosine A1 receptors have no anticonvulsant effect on piriform cortex-kindled seizures in rat

2006 ◽  
Vol 84 (8-9) ◽  
pp. 913-921 ◽  
Author(s):  
Parviz Shahabi ◽  
Javad Mirnajafi-Zadeh ◽  
Yaghoub Fathollahi ◽  
Narges Hoseinmardi ◽  
Mohammad Ebrahim Rezvani ◽  
...  
Keyword(s):  
Basolateral Amygdala ◽  
Critical Role ◽  
Piriform Cortex ◽  
Epileptic Seizures ◽  
Anticonvulsant Effect ◽  
Seizure Severity ◽  
Stage 4 ◽  
Dc Current ◽  
Kindled Seizures

Adenosine is an endogenous anticonvulsant that exerts its effects through A1 receptors. As the piriform/amygdala is a critical circuit for limbic seizure propagation, in this study, the role of basolateral amygdala A1 receptors on piriform cortex (PC)-kindled seizures was investigated. Rats were kindled by daily electrical stimulation of PC. In fully kindled animals, bilateral intra-amygdala N6-cyclohexyladenosine (CHA; 10–500 µmol/L, a selective A1 receptor agonist) had no effect on kindled-seizure parameters. However, bilateral intra-amygdala 2% lidocaine (reversal neuronal inhibitor) reduced the kindled seizure severity. There was significant increase in stage 4 latency and decrease in stage 5 duration. Bilateral lesion of basolateral amygdala of kindled animals (by electrical DC current) reduced the kindled seizure severity more dramatically. Our results showed afterdischarge duration, stage 5 duration, and seizure duration were decreased and stage 4 latency increased significantly. In addition, daily intra-amygdala CHA had no significant effect on PC kindling acquisition. Therefore, it may be concluded that although the basolateral amygdala neuronal activity has a critical role in the propagation of epileptic seizures from PC, the amygdala A1 receptors have no role in this regard. On the other hand, amygdala A1 receptors have no anticonvulsant or antiepileptogenic effect on PC-kindled seizures.

scholarly journals The Role of Piriform Cortex Adenosine A1 Receptors on Hippocampal Kindling

2008 ◽  
Vol 35 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Simin Namvar ◽  
Javad Mirnajafi-Zadeh ◽  
Yaghoub Fathollahi ◽  
Maryam Zeraati
Keyword(s):  
Electrical Stimulation ◽  
Critical Role ◽  
Piriform Cortex ◽  
Anticonvulsant Effect ◽  
Seizure Duration ◽  
Ca1 Region ◽  
Stage 4 ◽  
Kindled Seizures ◽  
Stimulation Of

Introduction:The hippocampus and piriform cortex have a critical role in seizure propagation. In this study, the role of adenosine A1 receptors of piriform cortex on CA1 hippocampal kindled seizures was studied in rats.Methods:Animals were implanted with a tripolar electrode in the right hippocampal CA1 region and two guide cannulae in the left and right piriform cortex. They were kindled by daily electrical stimulation of hippocampus. In fully kindled rats, N6- cyclohexyladenosine (CHA; a selective adenosine A1 receptors agonist) and 1, 3-dimethyl-8-cyclopenthylxanthine (CPT a selective adenosine A1 receptor antagonist) were microinfused into the piriform cortex. The animals were stimulated at 5, 15 and 90 minutes (min) after drag injection.Results:Obtained data showed that CHA (10 and 100 μM) reduced afterdischarge duration, stage 5 seizure duration, and total seizure duration at 5 and 15 min after drag injection. There was no significant change in latency to stage 4 seizure. CPT at concentration of 20 μM increased afterdischarge duration, stage 5 seizure duration, and total seizure duration and decreased latency to stage 4 seizure at 5 and 15 min post injection. Pretreatment of rats with CPT (10 μM), 5 min before CHA (100 μM), reduced the effect of CHA on seizure parameters.Conclusion:These results suggested that activity of adenosine A1 receptors in the piriform cortex has an anticonvulsant effect on kindled seizures resulting from electrical stimulation of the CA1 region of the hippocampus.

Anticonvulsant effect of A1 but not A2A adenosine receptors of piriform cortex in amygdala-kindled rats

2007 ◽  
Vol 85 (6) ◽  
pp. 606-612 ◽  
Author(s):  
Mohammad Ebrahim Rezvani ◽  
Javad Mirnajafi-Zadeh ◽  
Yaghoub Fathollahi ◽  
Mohammad Reza Palizvan
Keyword(s):  
Electrical Stimulation ◽  
Adenosine Receptors ◽  
Piriform Cortex ◽  
Anticonvulsant Effect ◽  
Seizure Duration ◽  
A2a Adenosine Receptors ◽  
Stage 4 ◽  
Kindled Seizures ◽  
Anticonvulsant Effects ◽  
Stimulation Of

In this study, the effect of A1 and A2A adenosine receptor activity of the piriform cortex (PC) on amygdala-kindled seizures was investigated in rats. Animals were kindled by daily electrical stimulation of the amygdala. In fully kindled rats, N6-cyclohexyladenosine (CHA, a selective A1 agonist), 8-cyclopentyl-1,3-dimethylxanthine (CPT, a selective A1 antagonist), CGS21680 hydrochloride (CGS, a selective A2A agonist), and ZM241385 (ZM, a selective A2A antagonist) were microinjected bilaterally into the PC. Rats were stimulated 5 min post-drug microinjection and seizure parameters were measured. Results showed that intra-PC CHA (10 and 100 μmol/L) decreased the duration of both afterdischarge and stage 5 seizure and significantly increased the latency to stage 4 seizure. Intra-PC CPT increased afterdischarge and stage 5 seizure duration at the dose of 20 μmol/L. The anticonvulsant effect of CHA (100 μmol/L) was eliminated by CPT (10 μmol/L) pretreatment. On the other hand, neither intra-PC CGS nor ZM had a significant effect on kindled seizures. These results suggest that activity of A1, but not A2A, receptors of the PC have anticonvulsant effects on kindled seizures elicited from electrical stimulation of the amygdala.

The role of adenosine A1 and A2A receptors of entorhinal cortex on piriform cortex kindled seizures in rats

2007 ◽  
Vol 56 (2) ◽  
pp. 110-117 ◽  
Author(s):  
N HOSSEINMARDI ◽  
J MIRNAJAFIZADEH ◽  
Y FATHOLLAHI ◽  
P SHAHABI
Keyword(s):  
Entorhinal Cortex ◽  
Piriform Cortex ◽  
A2a Receptors ◽  
Adenosine A1 ◽  
Kindled Seizures

scholarly journals Human extinction learning is accelerated by an angiotensin antagonist via ventromedial prefrontal cortex and its connections with basolateral amygdala

2019 ◽  
Author(s):  
Feng Zhou ◽  
Yayuan Geng ◽  
Fei Xin ◽  
Jialin Li ◽  
Pan Feng ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Basolateral Amygdala ◽  
Critical Role ◽  
Ventromedial Prefrontal Cortex ◽  
Extinction Learning ◽  
Multivoxel Pattern Analysis ◽  
Mediation Analyses ◽  
Link Type

AbstractRecent translational research suggests a role of the renin-angiotensin (RA) system in threat extinction and underlying neuroplasticity; however, whether and how pharmacological modulation of the RA system influences physiological and neural manifestations of threat during extinction learning in humans is unclear. Here we report that pre-extinction administration of losartan, an angiotensin II type 1 receptor antagonist, accelerated attenuation of physiological threat expression. During early extinction, losartan enhanced threat-signal specific ventromedial prefrontal cortex (vmPFC) activation and its coupling with the basolateral amygdala. Multivoxel pattern analysis revealed that losartan reduced whole brain, particularly vmPFC, threat expression and voxel-wise mediation analyses further confirmed that losartan-accelerated extinction crucially involved vmPFC processing. Overall the results provide initial evidence for a critical role of the RA system in extinction learning in humans and suggest that adjunct losartan administration may facilitate the efficacy of extinction-based therapies.ClinicalTrials.gov, Identifier: NCT03396523

scholarly journals Interaction between Thalamus and Hippocampus in Termination of Amygdala-Kindled Seizures in Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Zhen Zhang ◽  
Jia-Jia Li ◽  
Qin-Chi Lu ◽  
Hai-Qing Gong ◽  
Pei-Ji Liang ◽  
...  
Keyword(s):  
Information Flow ◽  
Basolateral Amygdala ◽  
Flow Direction ◽  
Neural Activities ◽  
Coupling Index ◽  
Stage 4 ◽  
Cornu Ammonis ◽  
Stage 1 ◽  
Kindled Seizures

The thalamus and hippocampus have been found both involved in the initiation, propagation, and termination of temporal lobe epilepsy. However, the interaction of these regions during seizures is not clear. The present study is to explore whether some regular patterns exist in their interaction during the termination of seizures. Multichannel in vivo recording techniques were used to record the neural activities from the cornu ammonis 1 (CA1) of hippocampus and mediodorsal thalamus (MDT) in mice. The mice were kindled by electrically stimulating basolateral amygdala neurons, and Racine’s rank standard was employed to classify the stage of behavioral responses (stage 1~5). The coupling index and directionality index were used to investigate the synchronization and information flow direction between CA1 and MDT. Two main results were found in this study.(1)High levels of synchronization between the thalamus and hippocampus were observed before the termination of seizures at stage 4~5 but after the termination of seizures at stage 1~2.(2)In the end of seizures at stage 4~5, the information tended to flow from MDT to CA1. Those results indicate that the synchronization and information flow direction between the thalamus and the hippocampus may participate in the termination of seizures.

scholarly journals Neuromodulation-induced burst firing in parvalbumin interneurons of the basolateral amygdala mediates transition between fear-associated network and behavioral states

2021 ◽  
Author(s):  
Xin Fu ◽  
Eric Teboul ◽  
Jamie Maguire ◽  
Jeffrey G Tasker
Keyword(s):  
Basolateral Amygdala ◽  
Critical Role ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Receptor Activation ◽  
Neuron Activity ◽  
Behavioral States ◽  
Fear Expression

Network orchestration of behavioral states involves coordinated oscillations within and between brain regions. The network communication between the basolateral amygdala (BLA) and the medial prefrontal cortex (PFC) plays a critical role in fear expression. Neuromodulatory systems play an essential role in regulating changes between behavioral states, however, a mechanistic understanding of how amygdalar circuits mediate transitions between brain and behavioral states remains largely unknown. Here, we examine the role of Gq-mediated neuromodulation of parvalbumin (PV)-expressing interneurons in the BLA in coordinating network and behavioral states using combined chemogenetics, patch clamp and field potential recordings. We demonstrate that Gq-signaling via hM3D designer receptor and α1 adrenoreceptor activation shifts the pattern of activity of the PV interneurons from tonic to phasic by stimulating a previously unknown, highly stereotyped bursting pattern of activity. This, in turn, generates bursts of inhibitory postsynaptic currents (IPSCs) and phasic firing in BLA principal neurons. The Gq-induced transition from tonic to phasic firing in BLA PV interneurons suppressed amygdalo-frontal gamma oscillations in vivo, consistent with the critical role of tonic PV neuron activity in gamma generation. The suppression of gamma oscillations by hM3D and α1 receptor activation in BLA PV interneurons also facilitated fear memory recall, in line with the inhibitory effect of gamma on fear expression. Thus, our data reveal a BLA parvalbumin neuron-specific neuromodulatory mechanism that mediates the transition to a fear-associated brain network state via regulation of amygdalo-frontal gamma oscillations.

scholarly journals A Critical Role of Basolateral Amygdala–to–Nucleus Accumbens Projection in Sleep Regulation of Reward Seeking

2020 ◽  
Vol 87 (11) ◽  
pp. 954-966 ◽  
Author(s):  
Yao Wang ◽  
Zheng Liu ◽  
Li Cai ◽  
Rong Guo ◽  
Yan Dong ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Basolateral Amygdala ◽  
Critical Role ◽  
Sleep Regulation ◽  
Reward Seeking

scholarly journals Basolateral amygdala to posterior piriform cortex connectivity ensures precision in learned odor threat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brett S. East ◽  
Gloria Fleming ◽  
Samantha Vervoordt ◽  
Prachi Shah ◽  
Regina M. Sullivan ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Stimulus Control ◽  
Local Field ◽  
Basolateral Amygdala ◽  
Piriform Cortex ◽  
Field Potential ◽  
Emotional States ◽  
Odor Perception ◽  
High Gamma

AbstractOdor perception can both evoke emotional states and be shaped by emotional or hedonic states. The amygdala complex plays an important role in recognition of, and response to, hedonically valenced stimuli, and has strong, reciprocal connectivity with the primary olfactory (piriform) cortex. Here, we used differential odor-threat conditioning in rats to test the role of basolateral amygdala (BLA) input to the piriform cortex in acquisition and expression of learned olfactory threat responses. Using local field potential recordings, we demonstrated that functional connectivity (high gamma band coherence) between the BLA and posterior piriform cortex (pPCX) is enhanced after differential threat conditioning. Optogenetic suppression of activity within the BLA prevents learned threat acquisition, as do lesions of the pPCX prior to threat conditioning (without inducing anosmia), suggesting that both regions are critical for acquisition of learned odor threat responses. However, optogenetic BLA suppression during testing did not impair threat response to the CS+ , but did induce generalization to the CS−. A similar loss of stimulus control and threat generalization was induced by selective optogenetic suppression of BLA input to pPCX. These results suggest an important role for amygdala-sensory cortical connectivity in shaping responses to threatening stimuli.

Secondary generalization of hippocampal kindled seizures in rats: examining the role of the piriform cortex

2002 ◽  
Vol 957 (1) ◽  
pp. 152-161 ◽  
Author(s):  
Mary Ellen Kelly ◽  
William A Staines ◽  
Dan C McIntyre
Keyword(s):  
Piriform Cortex ◽  
Kindled Seizures ◽  
Secondary Generalization

The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

2008 ◽  
Vol 15 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Amy Philofsky
Keyword(s):  
Language Development ◽  
Critical Role ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Children With Asd ◽  
Prevalence Estimates ◽  
Notable Increase ◽  
Screening Assessment ◽  
Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

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