Effects of ouabain on neuronal thermosensitivity in hypothalamic tissue slices

1989 ◽  
Vol 257 (1) ◽  
pp. R21-R28
Author(s):  
M. C. Curras ◽  
J. A. Boulant
Keyword(s):  
Firing Rate ◽  
Neuronal Activity ◽  
Unit Activity ◽  
Single Unit ◽  
Single Unit Activity ◽  
Tissue Slices ◽  
Temperature Changes ◽  
Cold Sensitive ◽  
Hypothalamic Tissue

To determine the role of the electrogenic Na+-K+ pump in neuronal thermosensitivity, single-unit activity was recorded in rat hypothalamic tissue slices before, during, and after perfusions containing 10(-5) or 10(-6) M ouabain, a specific pump inhibitor. Most neurons were recorded in the preoptic-anterior hypothalamus. Some neurons were also tested with high magnesium-low calcium perfusions to determine ouabain's effects on neuronal activity during synaptic blockade. When the neurons were characterized according to thermosensitivity, 24% were warm sensitive, 8% were cold sensitive, and 68% were temperature insensitive. Ouabain increased the firing rate of 60% of all neurons. Ouabain did not reduce the thermosensitivity of cold-sensitive and warm-sensitive neurons; however, temperature-insensitive neurons became more warm sensitive during ouabain perfusion. This increase in warm sensitivity did not occur with ouabain plus high Mg2+-low Ca2+ perfusion, suggesting that Ca2+ is important in this response. These results indicate that the Na-K pump is not responsible for the thermosensitivity of hypothalamic cold-sensitive or warm-sensitive neurons; however, this pump may be actively employed by many neurons that remain insensitive to temperature changes.

Thermosensitive single-unit activity of in vitro hypothalamic slices

1982 ◽  
Vol 242 (1) ◽  
pp. R77-R84 ◽  
Author(s):  
S. R. Kelso ◽  
M. N. Perlmutter ◽  
J. A. Boulant
Keyword(s):  
Firing Rate ◽  
Unit Activity ◽  
Single Unit ◽  
Animal Studies ◽  
Afferent Input ◽  
Single Unit Activity ◽  
Tissue Slices ◽  
Cold Sensitive ◽  
Inhibitory Synaptic Input

Single-unit activity was recorded in vitro from tissue slices of rat preoptic area-anterior hypothalamus. The thermosensitivity of 139 units was determined by their changes in firing rate in response to changes in slice temperature. Of these neurons, 30% were warm sensitive, 10% were cold sensitive, and 60% were temperature insensitive. These proportions are similar to results obtained in whole-animal studies, indicating that this is a viable preparation. It also suggests that hypothalamic neuronal thermosensitivity is not dependent on peripheral afferent input. All units had low firing rates (less than 10 imp/s) at 37 degrees C, and 83% of the warm-sensitive units were most thermosensitive above 37 degrees C. This supports the concept that afferent input determines the level of firing rate and range of thermosensitivity of warm-sensitive neurons. The cold-sensitive units also displayed maximal thermosensitivity above 37 degrees C, which would be expected if cold-sensitive neurons received inhibitory synaptic input from nearby warm-sensitive neurons.

Effect of synaptic blockade on thermosensitive neurons in hypothalamic tissue slices

1982 ◽  
Vol 243 (5) ◽  
pp. R480-R490 ◽  
Author(s):  
S. R. Kelso ◽  
J. A. Boulant
Keyword(s):  
Temperature Sensitivity ◽  
Single Unit ◽  
Preoptic Area ◽  
Tissue Perfusion ◽  
Single Unit Activity ◽  
Tissue Slices ◽  
Cold Sensitive ◽  
Hypothalamic Tissue ◽  
Independent Property

To understand the basis of hypothalamic neuronal thermosensitivity, single-unit activity was recorded in vitro, from constantly perfused tissue slices of rat preoptic area and anterior hypothalamus, PO/AH. The firing rate and thermosensitivity of individual PO/AH neurons was determined before, during, and after tissue perfusion with a synaptic blocking medium, containing elevated magnesium and decreased calcium concentrations. During synaptic blockade, thermosensitivity was retained in nearly all of the warm-sensitive neurons, and some temperature-insensitive neurons showed increased warm sensitivity. The thermosensitivity of all cold-sensitive neurons was lost during synaptic blockade. These results support the hypothesis that PO/AH cold-sensitive neurons depend on synapses from nearby warm-sensitive neurons for their temperature sensitivity; whereas warm sensitivity is an independent property of certain PO/AH neurons.

Single-Unit Activity of Hypothalamic Arcuate Neurons in Brain Tissue Slices

1986 ◽  
Vol 43 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Jenn-Tser Pan ◽  
Lee-Ming Kow ◽  
Donald W. Pfaff
Keyword(s):  
Brain Tissue ◽  
Unit Activity ◽  
Single Unit ◽  
Single Unit Activity ◽  
Tissue Slices ◽  
Arcuate Neurons

Failure of single-unit neuronal activity to differentiate globus pallidus internus and externus in Parkinson disease

2002 ◽  
Vol 97 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Steven J. Schiff ◽  
Brian K. Dunagan ◽  
Robert M. Worth
Keyword(s):  
Parkinson Disease ◽  
Globus Pallidus ◽  
Neuronal Activity ◽  
Unit Activity ◽  
Single Unit ◽  
Electrode Placement ◽  
Spike Sorting ◽  
Single Unit Activity ◽  
Content Type ◽  
Fine Print

Object. The authors examine the validity of single-unit neuronal recordings as a method of differentiating the globus pallidus internus (GPi) from the GP externus (GPe) in Parkinson Disease. Methods. One hundred twenty-eight recordings of apparent single-unit activity used to help guide final electrode placement in eight patients who underwent pallidotomy were analyzed using sophisticated spike sorting methods, and 185 neurons were characterized for mean firing frequency and percent of firing within bursts. In addition, the total spectral power was calculated on the full measured waveform for each of 128 samples without spike sorting. No correlation was identified between these measures of neuronal activity and depth within the GP. ConclusionsThese results call into question the validity of relying on single-unit activity and microelectrode recordings in the operating room to localize lesion or electrode placement within the GPi during stereotactic pallidal surgery.

scholarly journals Dynamic neuronal activation of a distributed cortico-basal ganglia-thalamus loop in learning a delayed sensorimotor task

2019 ◽  
Author(s):  
Xiaowei Gu ◽  
Chengyu T. Li
Keyword(s):  
Basal Ganglia ◽  
Neuronal Activity ◽  
Weak Interaction ◽  
Unit Activity ◽  
Single Unit ◽  
Premotor Cortex ◽  
Single Unit Activity ◽  
Functional Interaction ◽  
Sensorimotor Transformation ◽  
Related Information

AbstractThe cortico-basal ganglia-thalamus (CBT) loop is important for behavior. However, the activity and learning-related modulation within the loop in behavior remain unclear. To tackle this problem, we trained mice to perform a delayed sensorimotor-transformation task and recorded single-unit activity during learning simultaneously from four regions in a CBT loop: prelimbic area (PrL), posterior premotor cortex (pM2), dorsomedial caudate/putamen (dmCP), and mediodorsal thalamus (MD). Sensory and decision related information were encoded by the neurons within the loop, with weak interaction among neurons of different coding ability. The functional interaction among regions within the loop was dynamically routed in the loop during different behavioral phases and contributed to explain decision-related neuronal activity. The neurons of PrL and dmCP exhibited learning-related reorganization in neuronal activity and more persistent coding of sensory and decision-related information. Thus, both sensory- and decision-related information are processed in a functionally interacted CBT loop that is modulated by learning.

scholarly journals Effects of Methamphetamine on Single Unit Activity in Rat Medial Prefrontal Cortex In Vivo

2007 ◽  
Vol 2007 ◽  
pp. 1-9 ◽  
Author(s):  
Jinhwa Jang ◽  
Hee-Jin Ha ◽  
Yun Bok Kim ◽  
Young-Ki Chung ◽  
Min Whan Jung
Keyword(s):  
Prefrontal Cortex ◽  
Firing Rate ◽  
Medial Prefrontal Cortex ◽  
Unit Activity ◽  
Single Unit ◽  
Discharge Rate ◽  
Rate Change ◽  
Psychotic Symptoms ◽  
Single Unit Activity

To investigate how neuronal activity in the prefrontal cortex changes in an animal model of schizophrenia, we recorded single unit activity in the medial prefrontal cortex of urethane-anesthetized and awake rats following methamphetamine (MA) administration. Systemic MA injection (4 mg/kg, IP) induced inconsistent changes, that is, both enhancement and reduction, in unit discharge rate, with a subset of neurons transiently (<30 min) elevating their activities. The direction of firing rate change was poorly predicted by the mean firing rate or the degree of burst firing during the baseline period. Also, simultaneously recorded units showed opposite directions of firing rate change, indicating that recording location is a poor predictor of the direction of firing rate change. These results raise the possibility that systemic MA injection induces random bidirectional changes in prefrontal cortical unit activity, which may underlie some of MA-induced psychotic symptoms.

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