Quantitative receptor autoradiography using [3H]GABA under selective conditions was used to characterize the pharmacology, distribution, cellular localization, and development of GABAB binding sites in rodent cerebellum. Pharmacologic analysis of [3H]GABA binding showed that drugs active at GABAB receptors displaced [3H]GABA with the following order of potency: 3-aminopropylphosphonous acid > C...

BACKGROUND This study tests the hypothesis that loss of spinal activity of gamma-aminobutyric acid (GABA) contributes to the allodynia and hyperalgesia observed after peripheral nerve injury. METHODS Intrathecal catheters were implanted in male Sprague-Dawley rats. Antinociception was assessed by measuring withdrawal latency to immersion of the tail in a 52 degrees C water bath. Nerve injury ...

Activation of GABAB receptors in the Xenopus embryo, a simple vertebrate, causes presynaptic inhibition of transmitter release from glycinergic spinal neurons and an increase in action potential threshold. To investigate the underlying mechanisms of GABAB receptor action, we have made whole-cell voltage-clamp recordings from acutely isolated Xenopus embryo spinal neurons. The GABAB receptor ago...

The GABA-ergic and opioid modulation of neurally induced muscle responses was studied in isolated guinea-pig taenia coli and human colonic circular muscle, using identical field stimulation parameters (rectangular pulses of 0.5 ms duration, 9 V x cm(-1) intensity, trains of 3 pulses at 0.5 Hz, repeated every 1/3/5 min). The stimulation-induced contractions were inhibited in both preparations by...

Polygodial, a sesquiterpene isolated from the bark of Drymis winteri given systemically, intraplantarly, or by spinal or supraspinal sites, produced antinociception when assessed in both phases of the formalin test and against capsaicin-induced pain. Polygodial, even at high doses, had no antinociceptive or antihyperalgesic effect when assessed in hot-plate assay or in glutamate-induced hyperal...

The purpose of the present study was to characterize the ionic and pharmacological basis of the actions of synaptically released and exogenously applied GABA in basolateral amygdaloid pyramidal cells in vitro. Stimulation of forebrain afferents to pyramidal neurons in the basolateral amygdala evoked an excitatory postsynaptic potential followed by early and late inhibitory postsynaptic potentia...

Neurons in the brainstem auditory nuclei, n. magnocellularis and n. laminaris, of the chick are contacted by terminals containing the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). In this report we describe the physiological response of these neurons to GABA using an in vitro slice preparation. In brainstem auditory neurons, GABA produced a depolarization of up to 20 mV and an ass...

Baclofen is the P-chlorophenyl derivative of gamma-aminobutyric acid (GABA) derivative with an antispasmodic action and is used as a central acting muscle relaxant. GABA is a suppressive neurotransmitter widely distributed in the peripheral and central nervous systems (1). Baclofen [3-(p-Chlorophenyl)4-aminobutanoic acid], is a GABA B agonist. Baclofen has both presynaptic and post synaptic act...

Rioult-Pedotti, Mengia-Seraina. Intrinsic NMDA induced oscilto generate rhythmic motor behavior in spinal cords of the lations in motoneurons of an adult vertebrate spinal cord are lamprey (Sigvardt et al. 1985; Wallén and Grillner 1985, masked by inhibition. J. Neurophysiol. 77: 717–730, 1997. Low1987), tadpoles (Sillar and Simmers 1994), and neonatal frequency membrane potential oscillations ...

The pharmacological profile of the g-aminobutyric acid (GABA)B receptor regulating cholinergic twitch contraction in the guinea pig ileum myenteric plexus-longitudinal muscle preparation was investigated. GABA and (2)-baclofen inhibited the contraction, exhibiting quite close potencies (pD2 for GABA 5 5.70; pD2 for (2)-baclofen 5 5.33). The compound CGP 47656 also reduced the cholinergic twitch...