Electrophysiologic study

Electrophysiological studies (mainly using voltage-clamp and patch clamp) revealed the essential properties of the sodium channels kinetics of channel gating and selective ion permeation. Sodium channels are... 

A century ago, Fick proposed the concept of four primary tastes, namely, sweet, salty, sour, and bitter. It has since been found that taste sensations are not describable by a single collection of discrete primaries. Electrophysiological studies of afierent taste-units in the chorda tympani and glossophyrangeal nerves have revealed that a continuous spectrum of gustation may be based on these four taste elements. Furthermore, the intensities of the tastes that we commonly experience are due not only to gustatory sensations but also to tactile, hot and cold, and, above all, olfactory sensations. The complexities of taste studies are such that, unless one of the taste modalities is singled out for study, there is very little hope of success. 

Electrophysiological studies often demonstrate multiple, asymmetric mononeuropathies, usually axonal in type, that cannot be localized to typical sites of entrapment (Keswani et al. 2002). CSF analysis reveals nonspecific abnormalities, such as elevated protein and mild mononuclear pleocytosis. Polymerase chain reaction (PCR) for CMV DNA and nerve or muscle biopsy may provide more specific diagnostic data (Roullet et al. 1994). 

Electrophysiologic studies usually show axonal neuropathy, but in 15%, it is demyelinating (Moulignier et al. 1997). CSF is remarkable for a mild nonspecific lymphocytic pleocytosis, but with markedly raised protein up to 2 g/L (Brew 2003). Nerve biopsy shows marked angiocentric CD8 infiltrates without mural necrosis... 

Hu, XT and Wang, RY (1988) Comparison of effects of Dj and D2 dopamine receptor agonists on neurons in the rat caudate putamen an electrophysiological study. J. Neurosci. 8 4340-4348. 

Many electrophysiological studies have shown that single-unit activity of noradrenergic neurons in the locus coeruleus is increased by sensory stimuli. Effective stimuli range from those causing physical discomfort (e.g. footshock) and interoceptive... 

Chaput, Y, de Montigny, C and Blier, P (1991) Presynaptic and postsynaptic modifications of the serotonin system by long-term administration of antidepressant treatments. An in vivo electrophysiologic study in the rat. Neuropsychopharmacology 5 219-229. 

Coetzee, W.A. and Opie, L.Fl. (1992). Effects of oxygen free radicals on isolated cardiac myocytes from guinea-pig ventricle Electrophysiological studies. J. Mol. Cell. Cardiol. 24, 651-663. 

MacLeod N. and Reinhardt W. (1983). An electrophysiological study of the accessory olfactory bulb in rabbit — I. Analysis of electrical evoked potential fields. Neuroscience 10, 119-129. 

Meredith M. and Burghardt G. (1978). Electrophysiological studies of the tongue and accessory olfactory bulb in garter snakes. Physiol Behav 21, 1001-1108. 

Just a year after Stephenson s classical paper of 1956, J. del Castillo and B. Katz published an electrophysiological study of the interactions that occurred when pairs of agonists with related structures were applied simultaneously to the nicotinic receptors at the endplate region of skeletal muscle. Their findings could be best explained in terms of a model for receptor activation that has already been briefly introduced in Section 1.2.3 (see particularly Eq. (1.7)). In this scheme, the occupied receptor can isomerize between an active and an inactive state. This is very different from the classical model of Hill, Clark, and Gaddum in which no clear distinction was made between the occupation and activation of a receptor by an agonist. 

Ehle A. 1986. Lead neuropathy and electrophysiological studies in low level lead exposure A critical review. Neurotoxicity 7 203-216. 

Gronier, B. Rasmussen, K. (1998). Activation of midbrain presumed dopaminergic neurones by muscarinic cholinergic receptors an in vivo electrophysiological study in the rat. Br. J. Pharmacol. 124, 455-64. 

Vanni-Mercier, G Gigout, S., Debilly, G. Lin, J. S. (2003). Waking selective neurons in the posterior hypothalamus and their response to histamine H3-receptor ligands an electrophysiological study in freely moving cats. Behav. Brain. Res. 

Napier T. C., Potter P. E. (1989). Dopamine in the rat ventral pallidum/substantia innominata biochemical and electrophysiological studies. Neuropharmacology 28(7), 757-60. 

Immunohistochemical and electrophysiological studies of the hypothalamic preoptic area (POA), which plays a major role in sleep promotion, have identified a subset of sleep-active ventrolateral POA (VLPO) neurons (Sherin et al. 1996 Szymusiak et al. 1998). A tightly clustered group of VLPO neurons appears to promote non-REM sleep, by suppression of the histaminergic arousal system, which... 

A variety of different types of tissue preparation are used to study neurosecretion and synaptic transmission. A classical preparation is the frog NMJ (discussed below). The brain slice has been used for many years for biochemical studies of CNS metabolism and is a useful preparation for electrophysiological studies of synaptic transmission in the CNS. Slices can be oriented to maintain the local neuronal circuitry and can be thin, 0.3 mm, to minimize anoxia. The transverse hippocampal slice is widely used as an electrophysiological preparation to study synaptic plasticity (see Ch. 53). Primary cultures of neurons from selected CNS areas and sympathetic ganglia are also frequently used. They permit excellent visual identification of individual neurons and control of the extracellular milieu, but the normal neuronal connections are disrupted. 

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