The hippocampus plays an important role in learning and memory. Synaptic plasticity in the hippocampus, short-term and long-term, is postulated to be a neural substrate of memory trace. Paired-pulse stimulation is a standard technique for evaluating a form of short-term synaptic plasticity in rodents. However, evidence is lacking for paired-pulse responses in the primate hippocampus. In the pre...

Short-term facilitation is a widely observed form of synaptic enhancement that is not well understood. Although presynaptic calcium has long been implicated in this process, its role is unclear, particularly at synapses in the mammalian brain. We tested the role of presynaptic residual free calcium ([Ca]res) in facilitation of synapses between granule cells and Purkinje cells in rat cerebellar ...

OBJECTIVE The L-type Ca(2+) current (I(Ca,L)) contributes to the generation and modulation of the pacemaker action potential (AP). We investigated facilitation of I(Ca,L) in sino-atrial cells. METHODS Facilitation was studied in regularly-beating cells isolated enzymatically from young albino rabbits (0.8-1 kg). We used the whole-cell patch-clamp technique to vary the frequency of the test de...

Facilitation is a temporary increase in postsynaptic response to a presynaptic action potential or depolarization induced by a preceding presynaptic depolarization. It is distinguished from longer-term components of activity-dependent synaptic enhancement by its low activation threshold (a pair of action potentials is often sufficient, hence the term paired-pulse facilitation) and short persist...

The physiology and pharmacology of CA1 is changed in epilepsy. There is evidence that the thalamic input to CA1 has a somewhat different physiological effect compared with the CA3 input. In this study we sought to determine whether this difference in physiology persists in epilepsy, and whether there are changes in the pharmacologic profile of these responses. Under urethane two stimulating ele...

In the mustached bat, Pteronotus parnellii, neurons in the primary auditory cortex (AI) have been thought to respond primarily to single frequencies, as in other mammals. However, neurons in the Doppler-shifted constant-frequency (DSCF) area, a part of the mustached bat's AI that contains an overrepresentation of the prominent CF2 component of the biosonar signal, were found to show facilitativ...

OBJECTIVE Decay kinetics of the voltage-gated L-type Ca(2+) current (I(CaL)) control the magnitude of Ca(2+) influx during the cardiac action potential. We investigated the influence of changes in diastolic membrane potential on I(CaL) decay kinetics in cardiac cells. METHODS Cells were isolated enzymatically from rat ventricles, human right atrial appendages obtained during corrective heart ...

Consensus exists that lipids must play key functions in synaptic activity but precise mechanistic information is limited. Acid sphingomyelinase knockout mice (ASMko) are a suitable model to address the role of sphingolipids in synaptic regulation as they recapitulate a mental retardation syndrome, Niemann Pick disease type A (NPA), and their neurons have altered levels of sphingomyelin (SM) and...

Introduction: The primary somatosensory cortex has an important role in nociceptive sensory-discriminative processing. Altered peripheral inputs produced by deafferentation or by long-term changes in levels of afferent stimulation can result in plasticity of cortex. Capsaicin-induced depletion of C-fiber afferents results in plasticity of the somatosensory system. Plasticity includes short-term...