Contribution of zona incerta to osmotically induced drinking in rats

1986 ◽  
Vol 251 (5) ◽  
pp. R823-R832
Author(s):  
D. Mok ◽  
G. J. Mogenson

Spontaneous extracellular activity was recorded from single neurons in the rostral zona incerta (ZI) of urethan-anesthetized rats. Ventricular injections of hyperosmotic saline (1 or 2 microliter of NaCl solutions with osmolarities of 0.6 or 1.2 osmol/l) and distilled water (1 or 2 microliter) at the level of the anteroventral third ventricle (AV3V) changed the firing rate of ZI neurons. By comparison, ventricular injections of osmotic solutions at the level of the dorsal third ventricle were relatively ineffective. Injections of osmotic solutions (0.2 or 0.5 microliter of 1.2 osmol/l NaCl) into the medial preoptic area (MPO) also changed the firing rate of ZI neurons, whereas control injections into the caudate putamen were ineffective. In another series of rats, injections of procaine into the region of the rostral ZI significantly reduced drinking to injections of hyperosmotic saline into the ipsi- but not the contralateral MPO. The ZI, AV3V, and MPO have previously been reported to contribute to the neural regulation of fluid intake. These findings provide additional evidence for a role of the ZI in drinking and suggest that part of the central pathway for osmotic thirst involves a projection to neurons in the ZI from osmoreceptors in the MPO.

Endocrinology ◽  
2016 ◽  
Vol 157 (1) ◽  
pp. 323-335 ◽  
Author(s):  
Bruna Kalil ◽  
Aline B. Ribeiro ◽  
Cristiane M. Leite ◽  
Ernane T. Uchôa ◽  
Ruither O. Carolino ◽  
...  

Abstract In rodents, kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) of the preoptic area are considered to provide a major stimulatory input to the GnRH neuronal network that is responsible for triggering the preovulatory LH surge. Noradrenaline (NA) is one of the main modulators of GnRH release, and NA fibers are found in close apposition to kisspeptin neurons in the RP3V. Our objective was to interrogate the role of NA signaling in the kisspeptin control of GnRH secretion during the estradiol induced LH surge in ovariectomized rats, using prazosin, an α1-adrenergic receptor antagonist. In control rats, the estradiol-induced LH surge at 17 hours was associated with a significant increase in GnRH and kisspeptin content in the median eminence with the increase in kisspeptin preceding that of GnRH and LH. Prazosin, administered 5 and 3 hours prior to the predicted time of the LH surge truncated the LH surge and abolished the rise in GnRH and kisspeptin in the median eminence. In the preoptic area, prazosin blocked the increases in Kiss1 gene expression and kisspeptin content in association with a disruption in the expression of the clock genes, Per1 and Bmal1. Together these findings demonstrate for the first time that NA modulates kisspeptin synthesis in the RP3V through the activation of α1-adrenergic receptors prior to the initiation of the LH surge and indicate a potential role of α1-adrenergic signaling in the circadian-controlled pathway timing of the preovulatory LH surge.


2001 ◽  
Vol 281 (3) ◽  
pp. R971-R978 ◽  
Author(s):  
Stuart A. McCaughey ◽  
Michael G. Tordoff

Calcium-deprived rats develop a compensatory appetite for substances that contain calcium. To investigate the role of gustatory factors in calcium appetite, we recorded the extracellular activity of single neurons in the nucleus of the solitary tract of calcium-deprived and replete rats. The activity evoked by a broad array of taste stimuli was examined in 51 neurons from replete rats and 47 neurons from calcium-deprived rats. There were no differences between the groups in the responses of all neurons combined. However, neurons with sugar-oriented response profiles gave significantly larger responses to 3, 10, and 100 mM CaCl2in the calcium-deprived group than did corresponding cells in the replete group. This difference in taste-evoked responding may underlie an increase in the palatability of CaCl2 and, in turn, contribute to the expression of calcium appetite.


1975 ◽  
Vol 229 (3) ◽  
pp. 676-682 ◽  
Author(s):  
E Preston

The release of norepinephrine (NE) from nerve terminals in the anterior hypothalamic/preoptic area (AH/POA) of the rabbit may serve to raise body temperature. To further examine the putative neurotransmitter role of NE, bilateral microinjections of 5 or 10 mug NE were made into or near the AH/POA of 44 conscious rabbits exposed to an ambient temperature of 15 degrees C. Microinjections into the AH/POS did not cause fever; they either had no influence on thermoregulation or rapidly induced ear vasocilation and increased ear temperature accompanied by slight falls in rectal temperature. The latter averaged 0.32 degrees C (range: 0.16-0.45 degrees C) in 18 rabbits in which the effects were prominent. In contrast, the injection of 100 or 250 mug NE into the lateral cerebral ventricles of conscious rabbits in the 15 degrees C environment caused mean fevers of 0.62 +/- 0.0, and 1.04 +/- 0.14 degrees C (+/- SE, n equals 6), respectively, within 70 min. The febrile response to intraventricular injection of NE may be due to an action of the drug at a site other than the AH/POA. Alternatively, the response may depend critically on the particular distribution of NE that results from its diffusion from the third ventricle into the AH/POA.


2013 ◽  
Vol 109 (10) ◽  
pp. 2505-2516 ◽  
Author(s):  
Fu-Zen Shaw ◽  
Yi-Fang Liao ◽  
Ruei-Feng Chen ◽  
Yu-Hsing Huang ◽  
Rick C. S. Lin

The contribution of the zona incerta (ZI) of the thalamus on spike-wave discharges (SWDs) was investigated. Chronic recordings of bilateral cortices, bilateral vibrissa muscle, and unilateral ZI were performed in Long-Evans rats to examine the functional role of SWDs. Rhythmic ZI activity appeared at the beginning of SWD and was accompanied by higher-oscillation frequencies and larger spike magnitudes. Bilateral lidocaine injections into the mystacial pads led to a decreased oscillation frequency of SWDs, but the phenomenon of ZI-related spike magnitude enhancement was preserved. Moreover, 800-Hz ZI microstimulation terminates most of the SWDs and whisker twitching (WT; >80%). In contrast, 200-Hz ZI microstimulation selectively stops WTs but not SWDs. Stimulation of the thalamic ventroposteriomedial nucleus showed no obvious effect on terminating SWDs. A unilateral ZI lesion resulted in a significant reduction of 7- to 12-Hz power of both the ipsilateral cortical and contralateral vibrissae muscle activities during SWDs. Intraincertal microinfusion of muscimol showed a significant inhibition on SWDs. Our present data suggest that the ZI actively modulates the SWD magnitude and WT behavior.


2021 ◽  
Vol 11 (3) ◽  
pp. 393
Author(s):  
Alessandro Carollo ◽  
Jan Paolo Macapinlac Balagtas ◽  
Michelle Jin-Yee Neoh ◽  
Gianluca Esposito

Research investigating the neural substrates underpinning parental behaviour has recently gained momentum. Particularly, the hypothalamic medial preoptic area (MPOA) has been identified as a crucial region for parenting. The current study conducted a scientometric analysis of publications from 1 January 1972 to 19 January 2021 using CiteSpace software to determine trends in the scientific literature exploring the relationship between MPOA and parental behaviour. In total, 677 scientific papers were analysed, producing a network of 1509 nodes and 5498 links. Four major clusters were identified: “C-Fos Expression”, “Lactating Rat”, “Medial Preoptic Area Interaction” and “Parental Behavior”. Their content suggests an initial trend in which the properties of the MPOA in response to parental behavior were studied, followed by a growing attention towards the presence of a brain network, including the reward circuits, regulating such behavior. Furthermore, while attention was initially directed uniquely to maternal behavior, it has recently been extended to the understanding of paternal behaviors as well. Finally, although the majority of the studies were conducted on rodents, recent publications broaden the implications of previous documents to human parental behavior, giving insight into the mechanisms underlying postpartum depression. Potential directions in future works were also discussed.


Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2681-2688 ◽  
Author(s):  
Sathya Velmurugan ◽  
Paula J. Brunton ◽  
Gareth Leng ◽  
John A. Russell

Secretin is a 27-amino acid brain-gut peptide from duodenal S-cells. We tested the effects of systemic administration of secretin to simulate its postprandial release on neuroendocrine neurons of the supraoptic nucleus (SON) in urethane-anesthetized female rats. Secretin dose-dependently increased the firing rate of oxytocin neurons, more potently than cholecystokinin, and dose-dependently increased plasma oxytocin concentration. The effect of secretin on SON vasopressin neurons was also predominantly excitatory, in contrast to the inhibitory actions of cholecystokinin. To explore the involvement of noradrenergic inputs in secretin-induced excitation, benoxathian, an α1-adrenoceptor antagonist, was infused intracerebroventricularly. Benoxathian intracerebroventricular infusion blocked the excitation by secretin of both oxytocin and vasopressin neurons. To test the role of local noradrenaline release in the SON, benoxathian was microdialyzed onto the SON. The basal firing rate of oxytocin neurons was slightly reduced and the secretin-induced excitation was attenuated during benoxathian microdialysis. Hence, noradrenergic pathways mediate the excitation by systemic secretin of oxytocin neurons via α1-adrenoceptors in the SON. As both systemic secretin and oxytocin are involved in regulating gastrointestinal functions and natriuresis, systemically released secretin might act partly through oxytocin.


1999 ◽  
Vol 276 (1) ◽  
pp. H63-H70 ◽  
Author(s):  
Shereeni J. Veerasingham ◽  
Frans H. H. Leenen

To examine the role of the ventral anteroventral third ventricle (vAV3V) in the hypertension induced by chronic subcutaneous ouabain and intracerebroventricular hypertonic saline, neurons in this area were destroyed by microinjection of an excitotoxin, ibotenic acid. Sham-operated or lesioned Wistar rats were administered ouabain (50 μg/day) or placebo for 3 wk from subcutaneously implanted controlled release pellets or artificial cerebrospinal fluid (CSF) or CSF containing 0.8 mol/l NaCl (5 μl/h) infused intracerebroventricularly for 2 wk. At the end of the experiment, mean arterial pressure (MAP) and heart rate at rest and in response to ganglionic blockade by intravenous hexamethonium (30 mg/kg) were assessed. In rats infused with hypertonic saline, responses to air jet stress were also assessed. Baseline MAP in sham-operated rats receiving intracerebroventricular hypertonic saline or subcutaneous ouabain was significantly higher than in control rats (115 ± 1 vs. 97 ± 3 and 121 ± 3 vs. 103 ± 3 mmHg, respectively). vAV3V lesions abolished the increase in MAP elicited by chronic infusion of hypertonic saline or administration of ouabain. Sham-operated rats treated with hypertonic saline or ouabain exhibited significantly enhanced decreases in MAP to hexamethonium, but lesioned rats did not. Rats infused with hypertonic saline demonstrated enhanced responses to air jet stress that were similar in sham-operated and lesioned rats. These results demonstrate that neurons in the vAV3V are essential for the hypertension induced by intracerebroventricular hypertonic saline and subcutaneous ouabain, possibly by increasing sympathetic tone. Cardiovascular responses to air jet stress appear not to be mediated by the vAV3V.


Author(s):  
Judith Rudolph ◽  
Katrin Gerstmann ◽  
Geraldine Zimmer ◽  
André Steinecke ◽  
Annika Döding ◽  
...  

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