Benjamin Esplin

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1. A single administration of the ganglion blocker, chlorisondamine (10 mg kg-1, s.c.) is known to produce a quasi-irreversible blockade of the central actions of nicotine in the rat. The mechanism of this persistent action is not known. It is also unclear whether chlorisondamine can block neuronal responses to excitatory amino acids and whether chronic(More)
Tiagabine is a potent GABA uptake inhibitor with demonstrated anticonvulsant activity. GABA uptake inhibitors are believed to produce their anticonvulsant effects by prolonging the postsynaptic actions of GABA, released during episodes of neuronal hyperexcitability. However, tiagabine has recently been reported to facilitate the depolarizing actions of GABA(More)
The antiepileptic drug, gamma-vinyl GABA (GVG, vigabatrin), is an irreversible inhibitor of GABA-transaminase, the enzyme responsible for the breakdown of GABA. In hippocampal slices prepared from rats pretreated with either an anticonvulsant dose of GVG (1500 mg/kg) or saline, electrophysiological recordings were performed in order to examine the effects(More)
1. The transmission in the spinal monosynaptic pathway was studied during repetitive stimulation of a motor nerve by 10 stimuli at 2, 5, or 10 Hz in spinal cats. Initially, the amplitudes of the monosynaptic responses rapidly declined, reaching a plateau after a few stimuli. The level of the plateau was inversely related to the frequency of stimulation. 2.(More)
The effects of phencyclidine (PCP) and two dioxolane stereoisomers, dexoxadrol and levoxadrol, on hippocampal inhibition were compared. Field potentials were recorded in the CA1 pyramidal cell layer in the rat hippocampal slices in vitro. Recurrent inhibition of the population spikes evoked orthodromically by stimulation of the Schaffer collaterals was(More)
The acute effects of gamma-vinyl-GABA (GVG) on GABAergic inhibition were investigated in the hippocampal slice preparation using the paired-pulse test of inhibition during extracellular recordings. Superfusion of GVG (100-500 microM) for 60 min resulted in a concentration-dependent decrease in GABAergic inhibition. Slices superfused with higher(More)
The effects of phencyclidine and the dioxolane enantiomers, dexoxadrol and levoxadrol, on long-term potentiation in the hippocampus were compared. Field potentials were evoked by stimulation of Schaffer collaterals and recorded from the CA1 region. Long-term potentiation was induced by stimulation with a single train of 25 pulses at 50 Hz. The drugs were(More)
The effects of the competitive NMDA (N-methyl-D-aspartate) receptor antagonist, APV (2-amino-5-phosphonopentanoate; AP5), were examined in the hippocampal slice preparation. APV (50-100 microM) attenuated inhibition of the orthodromically evoked population spikes in the CA1 region produced by a conditioning stimulus to the alveus or to the stratum radiatum.(More)
The relationship of the depressant effect of baclofen on spinal monosynaptic transmission and its effect on the excitability of primary afferents was examined in spinal unanesthetized cats. Baclofen (1.0 mg/kg, i.v.) produced a deep and long-lasting depression of spinal reflex responses with a concomitant decrease of terminal excitability. Primary afferent(More)