Membrane properties of histaminergic tuberomammillary neurones of the rat hypothalamus in vitro.
- 1 May 1988
- journal article
- research article
- Published by Wiley in The Journal of Physiology
- Vol. 399 (1), 633-646
- https://doi.org/10.1113/jphysiol.1988.sp017100
Abstract
1. Intracellular recordings were obtained from neurones of the tuberomammillary nucleus in an in vitro explant of the rat hypothalamus. 2. Tuberomammillary neurones were spontaneously active (2.1 +/- 0.6 Hz) at the resting potential which was around -50 mV. Action potential amplitude was 75 +/- 8 mV (n = 9); mean mid-amplitude duration was 1.8 +/- 0.4 ms (n = 9). 3. The mean input resistance of tuberomammillary neurones was 176 +/- 42 M omega (n = 30), and the mean membrane time constant was 19.8 +/- 5.3 ms (n = 30). These neurones exhibited inward rectification with hyperpolarization from the resting potential, and transient outward rectification at the offset of hyperpolarizing electrotonic pulses. 4. Action potentials were followed by an after-hyperpolarization of 300-600 ms duration and 12-18 mV amplitude. This after-hyperpolarization had a reversal potential around -80 mV, was abolished by intracellular loading with caesium, and was reduced but not abolished by bath application of either cadmium, cobalt or nickel. 5. Tetrodotoxin abolished spontaneous action potentials. Further addition of tetraethylammonium ions revealed a regenerative spike which was reversibly blocked by the addition of cobalt. 6. That tuberomammillary neurones exhibiting these properties were indeed histaminergic was confirmed in five cases by intracellular ionophoresis of Lucifer Yellow and subsequent double labelling by immunofluorescent localization of the histamine synthetic enzyme L-histidine decarboxylase.This publication has 27 references indexed in Scilit:
- En bloc immunohistochemistry reveals extensive distribution of histidine decarboxylase-immunoreactive neurons on the ventral surface of the rat hypothalamusNeuroscience Letters, 1987
- Single-Channel and Genetic Analyses Reveal Two Distinct A-Type Potassium Channels in DrosophilaScience, 1987
- Voltage-dependent currents of vertebrate neurons and their role in membrane excitability.1986
- Electrophysiological and pharmacological characterization of serotonergic dorsal raphe neurons recorded extracellularly and intracellularly in rat brain slicesBrain Research, 1983
- Passive membrane properties of neurones in the dorsal raphe and periaqueductal grey recorded in vitroNeuroscience Letters, 1983
- Histamine and noradrenaline decrease calcium-activated potassium conductance in hippocampal pyramidal cellsNature, 1983
- M‐currents and other potassium currents in bullfrog sympathetic neuronesThe Journal of Physiology, 1982
- A transient outward current in a mammalian central neurone blocked by 4-aminopyridineNature, 1982
- Internal cesium ions block various K conductances in spinal motoneuronsCanadian Journal of Physiology and Pharmacology, 1981
- Calcium‐mediated inactivation of the calcium conductance in caesium‐loaded giant neurones of Aplysia californica.The Journal of Physiology, 1981