YAMANO, M. AND P. G. M. LUITEN. Direct synaptic contacts of medial septal efferents with somatostatin immunoreactive neurons in the rat hippocampus. BRAIN RES BULL 22(6) 993-1001, 1989.-Anterogradely labeled projections from the medial septum to hippocampal somatostatin immunoreactive (SOM-I) neurons were studied with double-label imrnunocytochemistry under light (LM) and electron microscopic (...

Abstract* Introduction: Chronic morphine exposure can cause addiction and affect synaptic plasticity, but the underlying neural mechanisms of this phenomenon remain unknown. Herein we used electrophysiologic approaches in hippocampal CA1 area to examine the effect of chronic morphine administration on short-term plasticity. Methods: Experiments were carried out on hippocampal slices taken f...

Myelin degeneration is one of the characteristics of aging and degenerative diseases. This study investigated age-related alterations in expression of myelin basic protein (MBP) in the hippocampal subregions (dentate gyrus, CA2/3 and CA1 areas) of gerbils of various ages; young (1 month), adult (6 months) and aged (24 months), using western blot and immunohistochemistry. Western blot results sh...

The brain operates through a coordinated interplay of numerous neurons, yet little is known about the collective behaviour of individual neurons embedded in a huge network. We used large-scale optical recordings to address synaptic integration in hundreds of neurons. In hippocampal slice cultures bolus-loaded with Ca2+ fluorophores, we stimulated the Schaffer collaterals and monitored the aggre...

Hippocampal long-term depression (LTD) is a long-lasting decrease in synaptic strength that is most commonly studied at glutamatergic inputs to pyramidal cells in hippocampal area CA1. Activation of G-protein-coupled group I (including types 1 and 5) metabotropic glutamate receptors (mGluRs) by the pharmacological agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) elicits LTD in area CA1 of the hip...

The actions of ethanol on gamma-aminobutyric acid-A (GABAA) receptor-mediated synaptic transmission in rat hippocampal CA1 neurons remain controversial. Recent studies have reported that intoxicating concentrations of ethanol (10-100 mM) can potentiate, inhibit, or have no effect on GABAA receptor-mediated synaptic responses in this brain region. The essential determinants of ethanol sensitivit...

Chronic flurazepam treatment substantially impairs the function of GABAergic synapses on hippocampal CA1 pyramidal cells. Previous findings included a significant decrease in the synaptic and unitary conductance of CA1 pyramidal neuron GABA(A) receptor channels and the appearance of a GABA(A)-receptor mediated depolarizing potential. To investigate the ionic basis of the decreased conductance, ...

Exogenous phospholipases have been used extensively as tools to study the role of membrane lipids in receptor mechanisms. We used in vitro quantitative autoradiography to evaluate the effect of phospholipase A2 (PLA2) on N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in rat brain. PLA2 pretreatment induced a significant increase in alpha-[3H]amino-3-hydroxy-5-methyl-isoxazole-4-pr...