Gamma oscillations in the entorhinal cortex of the freely behaving rat.

نویسندگان

  • J J Chrobak
  • G Buzsáki
چکیده

Gamma frequency field oscillations (40-100 Hz) are nested within theta oscillations in the dentate-hilar and CA1-CA3 regions of the hippocampus during exploratory behaviors. These oscillations reflect synchronized synaptic potentials that entrain the discharge of neuronal populations within the approximately 10-25 msec range. Using multisite recordings in freely behaving rats, we examined gamma oscillations within the superficial layers (I-III) of the entorhinal cortex. These oscillations increased in amplitude and regularity in association with entorhinal theta waves. Gamma waves showed an amplitude minimum and reversed in phase near the perisomatic region of layer II, indicating that they represent synchronized synaptic potentials impinging on layer II-III neurons. Theta and gamma oscillations in the entorhinal cortex were coupled with theta and gamma oscillations in the dentate hilar region. The majority of layer II-III neurons discharged irregularly but were phase-related to the negative peak of the local (layer II-III) gamma field oscillation. These findings demonstrate that layer II-III neurons discharge in temporally defined gamma windows (approximately 10-25 msec) coupled to the theta cycle. This transient temporal framework, which emerges in both the entorhinal cortex and the hippocampus, may allow spatially distributed subpopulations to form temporally defined ensembles. We speculate that the theta-gamma pattern in the discharge of these neurons is essential for effective neuronal communication and synaptic plasticity in the perforant pathway.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The effect of Gallic acid on prenatal entorhinal cortex and CA1/CA3 hippocampal areas in trimethyltin intoxication rat

Background: Prenatal intoxication with trimethyletin (TMT) induces widespread neuronal death in the central nervous system by inducing oxidative stress. The aim of this study was to evaluate the antioxidant effect of gallic acid (GA) on the neuronal density of the entorhinal cortex, hippocampal pyramidal cells and oxidative stress parameters in the fetal forebrain following TMT intoxication. ...

متن کامل

Impaired In Vivo Gamma Oscillations in the Medial Entorhinal Cortex of Knock-in Alzheimer Model

The entorhinal cortex (EC) has bidirectional connections with the hippocampus and plays a critical role in memory formation and retrieval. EC is one of the most vulnerable regions in the brain in early stages of Alzheimer's disease (AD), a neurodegenerative disease with progressive memory impairments. Accumulating evidence from healthy behaving animals indicates gamma oscillations (30-100 Hz) a...

متن کامل

Carbachol induces fast oscillations in the medial but not in the lateral entorhinal cortex of the isolated guinea pig brain.

Fast oscillations at 25-80 Hz (gamma activity) have been proposed to play a role in attention-related mechanisms and synaptic plasticity in cortical structures. Recently, it has been demonstrated that the preservation of the entorhinal cortex is necessary to maintain gamma oscillations in the hippocampus. Because gamma activity can be reproduced in vitro by cholinergic activation, this study ex...

متن کامل

Beta and gamma oscillatory activities associated with olfactory memory tasks: different rhythms for different functional networks?

Olfactory processing in behaving animals, even at early stages, is inextricable from top down influences associated with odor perception. The anatomy of the olfactory network (olfactory bulb, piriform, and entorhinal cortices) and its unique direct access to the limbic system makes it particularly attractive to study how sensory processing could be modulated by learning and memory. Moreover, ol...

متن کامل

Neuroprotective Effect of Gallic Acid on Memory Deficit and Content of BDNF in Brain Entorhinal Cortex of Rat’s Offspring in Uteroplacental Insufficiency Model

Introduction: Uteroplacental insufficiency (UPI) causes neurodevelopmental deficits affecting the intrauterine growth restricted (IUGR) offspring. This study aimed to analyze the effects of Gallic acid (GA) on memory deficit and brain-derived neurotrophic factor (BDNF) content in entorhinal cortex of UPI rat models. Methods: In this experimental study, 40 pregnant Wistar rats were randomly div...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The Journal of neuroscience : the official journal of the Society for Neuroscience

دوره 18 1  شماره 

صفحات  -

تاریخ انتشار 1998