Interaction between central and peripheral temperature signals on temperature-sensitive hypothalamic neurons

1977 ◽  
Vol 8 (6) ◽  
pp. 461-465
Author(s):  
L. P. Dymnikova ◽  
D. Kushakov
Keyword(s):  
Temperature Sensitive ◽  
Hypothalamic Neurons ◽  
Peripheral Temperature

Cyclic GMP alters the firing rate and thermosensitivity of hypothalamic neurons

2008 ◽  
Vol 294 (5) ◽  
pp. R1704-R1715 ◽  
Author(s):  
Chadwick L. Wright ◽  
Penny W. Burgoon ◽  
Georgia A. Bishop ◽  
Jack A. Boulant
Keyword(s):  
Firing Rate ◽  
Cyclic Nucleotide ◽  
Temperature Sensitive ◽  
Tissue Slices ◽  
Hypothalamic Neurons ◽  
Ambient Temperatures ◽  
Thermoregulatory Responses ◽  
Gated Channel ◽  
Cgmp Analog ◽  
Rostral Hypothalamus

The rostral hypothalamus, especially the preoptic-anterior hypothalamus (POAH), contains temperature-sensitive and -insensitive neurons that form synaptic networks to control thermoregulatory responses. Previous studies suggest that the cyclic nucleotide cGMP is an important mediator in this neuronal network, since hypothalamic microinjections of cGMP analogs produce hypothermia in several species. In the present study, immunohistochemisty showed that rostral hypothalamic neurons contain cGMP, guanylate cyclase (necessary for cGMP synthesis), and CNG A2 (an important cyclic nucleotide-gated channel). Extracellular electrophysiological activity was recorded from different types of neurons in rat hypothalamic tissue slices. Each recorded neuron was classified according to its thermosensitivity as well as its firing rate response to 2–100 μM 8-bromo-cGMP (a membrane-permeable cGMP analog). cGMP has specific effects on different neurons in the rostral hypothalamus. In the POAH, the cGMP analog decreased the spontaneous firing rate in 45% of temperature-sensitive and -insensitive neurons, an effect that is likely due to cGMP-enhanced hyperpolarizing K+ currents. This decreased POAH activity could attenuate thermoregulatory responses and produce hypothermia during exposures to cool or neutral ambient temperatures. Although 8-bromo-cGMP did not affect the thermosensitivity of most POAH neurons, it did increase the warm sensitivity of neurons in other hypothalamic regions located dorsal, lateral, and posterior to the POAH. This increased thermosensitivity may be due to pacemaker currents that are facilitated by cyclic nucleotides. If some of these non-POAH thermosensitive neurons promote heat loss or inhibit heat production, then their increased thermosensitivity could contribute to cGMP-induced decreases in body temperature.

Ethanol effects on temperature-sensitive hypothalamic neurons in rat brain slices

2004 ◽  
Vol 29 (7-8) ◽  
pp. 345-350 ◽  
Author(s):  
Bastian T. Wollweber ◽  
Horst Schneider ◽  
Karlheinz Voigt ◽  
Hans A. Braun
Keyword(s):  
Rat Brain ◽  
Brain Slices ◽  
Temperature Sensitive ◽  
Hypothalamic Neurons

Carbon dioxide and pH effects on temperature-sensitive and -insensitive hypothalamic neurons

2007 ◽  
Vol 102 (4) ◽  
pp. 1357-1366 ◽  
Author(s):  
Chadwick L. Wright ◽  
Jack A. Boulant
Keyword(s):  
Heat Stroke ◽  
Ph Effects ◽  
Temperature Sensitive ◽  
Sprague Dawley ◽  
Tissue Slices ◽  
Hypothalamic Neurons ◽  
Electrophysiological Recordings ◽  
Sprague Dawley Rats ◽  
Hypothalamic Tissue ◽  
Solution Bathing

The preoptic-anterior hypothalamus (POAH) controls body temperature, and thermoregulatory responses are impaired during hypercapnia. If increased CO2 or its accompanying acidosis inhibits warm-sensitive POAH neurons, this could provide an explanation for thermoregulatory impairment during hypercapnia. To test this possibility, extracellular electrophysiological recordings determined the effects of CO2 and pH on the firing rates of both temperature-sensitive and -insensitive neurons in hypothalamic tissue slices from 89 male Sprague-Dawley rats. Firing rate activity was recorded in 121 hypothalamic neurons before, during, and after changing the CO2 concentration aerating the tissue slice chamber or changing the pH of the solution bathing the tissue slices. Increasing the aeration CO2 concentration from 5% (control) to 10% (hypercapnic) had no effect on most (i.e., 69%) POAH temperature-insensitive neurons; however, this hypercapnia inhibited the majority (i.e., 59%) of warm-sensitive neurons. CO2 affected similar proportions of (non-POAH) neurons in other hypothalamic regions. These CO2 effects appear to be due to changes in pH since the CO2-affected neurons responded similarly to isocapnic acidosis (i.e., normal CO2 and decreased pH) but were not responsive to isohydric hypercapnia (i.e., increased CO2 and normal pH). These findings may offer a neural explanation for some heat-related illnesses (e.g., exertional heat stroke) where impaired heat loss is associated with acidosis.

Oncogenesis and the Lucké Virus

1968 ◽  
Vol 26 ◽  
pp. 200-201
Author(s):  
A. E. Vatter ◽  
J. Zambernard
Keyword(s):  
Rna Viruses ◽  
Vegetative State ◽  
Temperature Sensitive ◽  
Structural Level ◽  
Oncogenic Viruses ◽  
Dna Viruses ◽  
Leopard Frogs ◽  
Renal Adenocarcinoma ◽  
Induced Tumors ◽  
Northern Leopard Frogs

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.

THEORETICAL ELECTRON DENSITY AND TEMPERATURE SENSITIVE EMISSION LINE RATIOS FOR HELIUM-LIKE Si XIII COMPARED TO DITE TOKAMAK OBSERVATIONS

1989 ◽  
Vol 50 (C1) ◽  
pp. C1-559-C1-564
Author(s):  
F. P. KEENAN ◽  
R. BARNSLEY ◽  
J. DUNN ◽  
K. D. EVANS ◽  
S. M. McCANN ◽  
...  
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
Temperature Sensitive ◽  
Electron Density And Temperature

Synthetic and secretory activity of oxytocin-producing hypothalamic neurons

1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S111
Author(s):  
G. F. JIRIKOWSKI ◽  
F. ORTIGAO ◽  
CH. PILGRIM ◽  
H. SELIGER
Keyword(s):  
Secretory Activity ◽  
Hypothalamic Neurons

Origin of secretory activity of magnocellular hypothalamic neurons in vivo

1989 ◽  
Vol 120 (3_Suppl) ◽  
pp. S231-S232
Author(s):  
M. KLEMPT ◽  
F. ELLENDORFF ◽  
R. GROSSMANN
Keyword(s):  
Secretory Activity ◽  
Hypothalamic Neurons
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