Activation of neurons in the ventrolateral region of the periaqueductal gray (vlPAG) can elicit a decrease in renal sympathetic nerve activity and blood pressure. The present study investigated whether the vlPAG-evoked sympathoinhibitory response depends on neurons in the caudal midline medulla (CMM). In pentobarbital-anesthetized rats, activation of neurons in the vlPAG evoked a decrease in re...

Recent studies implicate the hippocampus in contextual memory retrieval. The present experiments explore this possibility by examining the impact of reversible inactivation of the dorsal hippocampus (DH) on the context-specific expression of extinction. In experiment 1, rats were conditioned to fear a tone conditional stimulus (CS) and subsequently extinguished either in the same context as con...

Colocalization of indoleamine uptake and GABA-like immunoreactivity was studied in the cat retina. Consecutive, semithin sections were incubated in antisera to either 5-HT (5-hydroxytryptamine) or GABA. More than 90% of all 5-HT-accumulating amacrine cells expressed GABA-like antigens. With the same approach, the colocalization of 5-HT uptake and GABA-like immunoreactivity was studied in rabbit...

introduction: aggressive behavior is a major issue in the field of mental health. pharmacotherapy is often used for the treatment of violent individuals. a neurochemical system most consistently linked with aggression is the gabaergic system. the aim of the present investigation was to examine the effect of muscimol (gabaa agonist) 250 and 500 ng/rat and picrotoxin (gabaa antagonist) 1.5 and 3 ...

These experiments examined the effects of pre-test intra dorsal hippocampus (intra-CA1) administration of GABAA receptor agonist and antagonist, muscimol and bicuculline respectively, on state-dependent learning induced by lithium. Male NMRI mice were trained in a one-trial step-down inhibitory avoidance task, and immediately after training they received IP injections of either saline (10 mL/kg...

Sodium-independent [ZH]GABA and [3H]muscimol binding was determined in adult rat cerebral cortical and spinal cord membranes and in membranes from fetal mouse cortical and spinal cord neurons in primary dissociated cell culture. In adult rat cerebral cortical membranes, [aH]GABA bound to two sites (Ka -8 nM, Bmax -0.62 pmol/mg protein; Ka : 390 nM, Bmax -3.9 pmol/mg protein) whereas the GABA ag...

Intracranial cannula along with electrodes was stereotaxically implanted in medial preoptic area of male rats. The electrical activity of mPOA was recorded before and after microinjection of GABA (0.5 micrograms/02 microliters), muscimol (0.5 micrograms/0.2 microliter), picrotoxin (0.25 micrograms/0.2 microliter) and their respective controls. Generalized slowing with an increase in amplitude a...

The effect of cold-immobilized stress on the gamma-aminobutylic acid (GABA)/benzodiazepine (BZP) receptor complex in the rat striatum was examined. The stressful manipulation induced a significant decrease in the amount of [3H]muscimol binding sites in the striatal particulate fraction. On the other hand, [3H]flunitrazepam (FLN) binding and the enhancing effect of FLN or secobarbital on the [3H...

3H-Muscimol, a structural analog of y-aminobutyric acid (GABA) , binds to rat brain synaptic membranes in a saturable manner, with a high affinity dissociation constant of 2.2 nM. Binding is increased in membranes that have been treated with Triton X-1Q0 and is not 3 dependent upon sodium. High affinity H-muscimol binding is regionally distributed, with highest binding density in the cerebellum...