Subfornical organ and supraoptic nucleus connections with septal neurons in rats

1985 ◽  
Vol 249 (2) ◽  
pp. R214-R218 ◽  
Author(s):  
A. V. Ferguson ◽  
C. W. Bourque ◽  
L. P. Renaud
Keyword(s):  
Supraoptic Nucleus ◽  
Medial Septum ◽  
Brain Regions ◽  
Subfornical Organ ◽  
Sprague Dawley ◽  
Indirect Pathway ◽  
Antidromic Activation ◽  
Diagonal Band ◽  
Sprague Dawley Rats ◽  
Septal Neurons

Extracellular single unit recordings obtained in pentobarbital-anesthetized male Sprague Dawley rats were utilized to examine the electrophysiology of connections of medial septum-diagonal band of Broca (MS-DBB) neurons with the subfornical organ (SFO), hippocampal commissure (HC), and supraoptic nucleus (SON). Of the 119/216 cells tested that demonstrated antidromic activation from SON, many (60%) were orthodromically excited by SFO stimulation, whereas most (68%) were unresponsive to stimulation in the adjacent HC. Separate populations of MS-DBB neurons that displayed antidromic activation from the SFO (11/140 cells tested) or HC (24/78 tested) were orthodromically excited by SON stimulation. Three cells were activated antidromically from both the SFO and SON. These observations reveal some possible interconnections between these three brain regions and point to the existence of an indirect pathway whereby the SFO can influence SON neurons through an influence on MS-DBB neurons.

Subfornical organ and cardiovascular influences on identified septal neurons

1988 ◽  
Vol 254 (3) ◽  
pp. R544-R551 ◽  
Author(s):  
S. D. Donevan ◽  
A. V. Ferguson
Keyword(s):  
Blood Pressure ◽  
Medial Septum ◽  
Subfornical Organ ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Diagonal Band ◽  
Sprague Dawley Rats ◽  
Relay Neuron ◽  
Afferent Information ◽  
Septal Neurons

We have identified, in urethan-anesthetized male Sprague-Dawley rats, a polysynaptic pathway connecting the subfornical organ (SFO) with the paraventricular nucleus (PVN) with a relay neuron in the medial septum-diagonal band of Broca (MS-DBB). Extracellular recordings were obtained from 136 MS-DBB neurons antidromically identified as projecting to the PVN. SFO stimulation orthodromically activated 79% of these cells (mean latency, 21.2 +/- 0.6 ms; mean duration, 6.0 +/- 0.2 ms), whereas stimulation in the fornix or hippocampal commissure had no effect. Of 35 identified MS-DBB neurons tested with systemic angiotensin II (ANG II), eight showed increases and six decreases in excitability that coincided with the ANG II-induced increase in blood pressure. To determine whether such changes were blood pressure related, 23 of the 35 identified MS-DBB neurons tested with ANG II were tested with systemic epinephrine. In every case the effect of epinephrine was similar to that of ANG II. These findings suggest that neurons in the MS-DBB receive afferent information from the SFO and the cardiovascular system. These cells in turn may activate neurons involved in the control of a variety of autonomic functions.

Role of the locus ceruleus in baroreceptor regulation of supraoptic vasopressin neurons in the rat

2000 ◽  
Vol 279 (1) ◽  
pp. R306-R319 ◽  
Author(s):  
Ryan J. Grindstaff ◽  
Regina R. Grindstaff ◽  
Margaret J. Sullivan ◽  
J. Thomas Cunningham
Keyword(s):  
Supraoptic Nucleus ◽  
Ibotenic Acid ◽  
Locus Ceruleus ◽  
Noradrenergic Neurons ◽  
Sprague Dawley ◽  
Diagonal Band ◽  
Sprague Dawley Rats ◽  
Phenylephrine Infusion ◽  
Vasopressin Neurons ◽  
Baroreceptor Activation

The goal of this study was to identify the source of baroreceptor-related noradrenergic innervation of the diagonal band of Broca (DBB). Male Sprague-Dawley rats underwent sinoaortic denervation (SAD, n = 13) or sham SAD surgery ( n = 13). We examined Fos expression produced by baroreceptor activation and dopamine-β-hydroxylase immunofluorescence in hindbrain regions that contain noradrenergic neurons. Baroreceptors were stimulated by increasing blood pressure >40 mmHg with phenylephrine (10 μg · kg−1· min−1 iv) in sham SAD and SAD rats. Controls were infused with 0.9% saline. Only the locus ceruleus (LC) demonstrated a baroreceptor-dependent increase in Fos immunoreactivity in dopamine-β-hydroxylase-positive neurons. In a second experiment, normal rats received rhodamine-labeled microsphere injections in the DBB ( n = 12) before phenylephrine or vehicle infusion. In these experiments, only the LC consistently contained Fos-positive cells after phenylephrine infusion that were retrogradely labeled from the DBB. Finally, we lesioned the LC with ibotenic acid and obtained extracellular recordings from identified vasopressin neurons in the supraoptic nucleus. LC lesions significantly reduced the number of vasopressin neurons that were inhibited by acute baroreceptor stimulation. Together, these results suggest that noradrenergic neurons in the LC participate in the baroreflex activation of the DBB and may thus be important in the baroreflex inhibition of vasopressin-releasing neurons in the supraoptic nucleus.

Enzymatic condensation of dopamine and acetaldehyde: a salsolinol synthase from rat brain

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Xuechai Chen ◽  
Abida Arshad ◽  
Hong Qing ◽  
Rui Wang ◽  
Jianqing Lu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Substantia Nigra ◽  
Human Subjects ◽  
Enzymatic Reaction ◽  
Brain Regions ◽  
Activity Detection ◽  
Reaction Products ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Salsolinol Synthase

AbstractSalsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline; Sal) is structurally similar to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which is supposed to have a role in the development of Parkinson-like syndrome in both human and non-human subjects. In the human brain, the amount of (R)-enantiomer of Sal is much higher than (S)-enantiomer, suggesting that a putative enzyme may participate in the synthesis of (R)-salsolinol, called (R)-salsolinol synthase. In this study, the (R)-salsolinol synthase activity in the condensation of dopamine and acetaldehyde was investigated in the crude extracts from the brains of Sprague Dawley rats. Identification of the enzymatic reaction products and enzyme activity detection were achieved by HPLC-electrochemical detection. The discovery of this enzyme activity in rat’s brain indicates the natural existence of (R)-salsolinol synthase in the brains of humans and rats, and it is distributed in most brain regions of rat with higher activity in soluble proteins extracted from striatum and substantia nigra.

Cardiovascular and renal sympathetic activation by blood-borne TNF-α in rat: the role of central prostaglandins

2003 ◽  
Vol 284 (4) ◽  
pp. R916-R927 ◽  
Author(s):  
Zhi-Hua Zhang ◽  
Shun-Guang Wei ◽  
Joseph Francis ◽  
Robert B. Felder
Keyword(s):  
Lateral Ventricle ◽  
Biological Effects ◽  
Brain Regions ◽  
Ventrolateral Medulla ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Tnf Α ◽  
Hypothalamic Level ◽  
Renal Sympathetic

In pathophysiological conditions, increased blood-borne TNF-α induces a broad range of biological effects, including activation of the hypothalamic-pituitary-adrenal axis and sympathetic drive. In urethane-anesthetized adult Sprague-Dawley rats, we examined the mechanisms by which blood-borne TNF-α activates neurons in paraventricular nucleus (PVN) of hypothalamus and rostral ventrolateral medulla (RVLM), two critical brain regions regulating sympathetic drive in normal and pathophysiological conditions. TNF-α (0.5 μg/kg), administered intravenously or into ipsilateral carotid artery (ICA), activated PVN and RLVM neurons and increased sympathetic nerve activity, arterial pressure, and heart rate. Responses to intravenous TNF-α were not affected by vagotomy but were reduced by mid-collicular decerebration. Responses to ICA TNF-α were substantially reduced by injection of the cyclooxygenase inhibitor ketorolac (150 μg) into lateral ventricle. Injection of PGE2 (50 ng) into lateral ventricle or directly into PVN increased PVN or RVLM activity, respectively, and sympathetic drive, with shorter onset latency than blood-borne TNF-α. These findings suggest that blood-borne cytokines stimulate cardiovascular and renal sympathetic responses via a prostaglandin-dependent mechanism operating at the hypothalamic level.

Opioidergic system and N-methyl D-aspartate receptor (NMDA-R) hypofunction: Translational implications for the pathophysiology of psychosis and drug addiction

2011 ◽  
Vol 26 (S2) ◽  
pp. 1231-1231
Author(s):  
E.F. Buonaguro ◽  
F. Marmo ◽  
L. Avvisati ◽  
G. Latte ◽  
R. Rossi ◽  
...  
Keyword(s):  
Drug Addiction ◽  
Drugs Of Abuse ◽  
Premotor Cortex ◽  
Region Of Interest ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Preclinical Model ◽  
Sprague Dawley ◽  
Somatosensory Cortices ◽  
Sprague Dawley Rats

Enkephalin is an opioidergic neuromodulator that has been implicated in long-term behavioural sensitization after administration of drugs of abuse. Enkephalin is also a molecular marker of GABAergic neurons in the striato-pallidal pathway that is involved in sensory-motor gating and has been considered dysfunctional in the pathophysiology of psychosis.In this study we investigated in male Sprague Dawley rats putative changes in Enkephalin transcripts by in situ hybridization after acute or subchronic administration of ketamine in either high or low subanaesthetic doses (50 mg/kg and 12 mg/kg respectively). Ketamine is a non-competitive NMDA-R antagonist that perturbs glutamate neurotransmission and provides a preclinical model of psychosis-like behaviour in rats.In the acute paradigm the expression of Enkephalin was reduced in the motor, premotor, somatosensory cortices as well as in anterior cingulate. In the subchronic paradigm Enkephalin expression was reduced in the premotor cortex, in the ventromedial caudate-putamen and in the shell of nucleus accumbens. Comparative analysis showed that the relative decrement in gene expression was not significantly different between the acute and subchronic paradigm for each region of interest.Changes in distribution of Enkephalin expression and correlation analysis of functionally related brain regions suggest that Enkephalin transcripts reduction may be implicated in the motivational aspects of drug addiction and may help explaining some aspects of the pathophysiology in ketamine-induced psychosis.

scholarly journals Raspberry Consumption Attenuates Angiotensin II-Induced Oxidative Stress in the Subfornical Organ in Male Sprague-Dawley Rats

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 298-298
Author(s):  
Jasmynne Blacks ◽  
Ferdinand Althammer ◽  
Rami Najjar ◽  
Maureen Meister ◽  
Jessica Dahn ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Subfornical Organ ◽  
Saline Control ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Funding Sources ◽  
Food Research ◽  
Food And Agriculture ◽  
Sprague Dawley Rats ◽  
Freeze Dried

Abstract Objectives To examine whether raspberry (RB) attenuates oxidative stress induced by angiotensin (Ang) II in the subfornical organ (SFO) of the brain in rats. Methods Male Sprague-Dawley rats were fed an AIN-93M diet with or without 10% w/w freeze-dried RB powder for seven weeks. At week 4, rats were implanted with subcutaneous osmotic minipumps that delivered 0.9% saline (Control) or Ang II (270 ng/kg body weight/day) for another three weeks. Brain region-specific tissue punches were collected from flash-frozen sections containing the SFO. NADPH oxidase (NOX) 2 and 4 and superoxide dismutase (SOD) 1 and 2 were measured in SFO using western blot. Results were analyzed using one-way ANOVA followed by Tukey post hoc test. Data were normalized to control and are expressed as means ± standard deviation. Results Ang II significantly increased NOX2 expression compared to control (1.24 ± 0.1, n = 5, vs 1.00 ± 0.07-fold, n = 3, P = 0.009) while RB supplementation significantly attenuated Ang II-induced increases in NOX2 (0.91 ± 0.05-fold, n = 4; P = 0.0006). Ang II also increased NOX4 expression compared to control (2.11 ± 1.2, n = 9, vs 0.98 ± 0.4-fold, n = 6, P = 0.04), but RB supplementation did not significantly attenuate this effect (1.30 ± 0.36-fold, n = 10, P = 0.11). RB increased expression of SOD1 (1.52 ± 0.20-fold, n = 4) compared to control (1.00 ± 0.15-fold, n = 3, P = 0.009) and Ang II alone (1.08 ± 0.16-fold, n = 5, P = 0.01). On the other hand, Ang II treatment decreased SOD2 expression compared to control (0.62 ± 0.05, n = 5, vs 1.00 ± 0.09-fold, n = 3, P = 0.0001), but the RB supplementation did not prevent this effect (0.72 ± 0.07-fold, n = 4, P = 0.16). Conclusions Our findings suggest that RB supplementation decreases Ang II-induced oxidative stress in the SFO by decreasing NOX2 and increasing SOD1 expression. Future investigations are warranted to elucidate the effects of RB on oxidative stress pathways in the SFO. Funding Sources This work was supported by the Agriculture and Food Research Initiative (grant no. 2019–67,017-29,257/project accession no. 1,018,642) from the USDA National Institute of Food and Agriculture.

Abstract 211: Delayed Cell Death in CA1 Region in a Cardiac Arrest Rat Model: Continuing After 2 Weeks of Survival?

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Sandra Högler ◽  
Ursula Teubenbacher ◽  
Wolfgang Weihs ◽  
Fritz Sterz ◽  
Ingrid A M Magnet ◽  
...  
Keyword(s):  
Cell Death ◽  
Cardiac Arrest ◽  
Brain Regions ◽  
Spontaneous Circulation ◽  
Sprague Dawley ◽  
Ca1 Region ◽  
Delayed Cell Death ◽  
Time Period ◽  
Sprague Dawley Rats ◽  
Hematoxylin Eosin

Background: Evolution of histological lesions in selectively vulnerable brain regions in animal models of cardiac arrest (CA)give evidence of potential therapeutic windows. Delayed cell death is of special interest in this regard. Methods: In male Sprague-Dawley rats (350g) ventricular fibrillation (VF) CA was induced for 6 min followed by chest compressions, ventilation and drugs for 2 min. To achieve return of spontaneous circulation animals were defibrillated every 2 min. Animals were sacrificed after one week (n=5) or two weeks (n=7) of survival and compared to four sham animals. Brains were fixed in formalin, embedded in paraffin wax and cut into 3 μm thick coronary sections for histological examination. Viable neurons with nucleolus were counted in Hematoxylin-Eosin (HE)-stained sections in a 250 μm sector of the medial CA1 region. FluoroJade B staining was applied to count dying neurons in the same sector. Results: In HE-staining sham animals had 31±4 viable neurons. In one week survivors 11±9 viable neurons (p=0.003) and in two week survivors 7±7 viable neurons (p=0.001 vs sham, p=0.49 vs one week survivors) were counted. Furthermore, a lot of degenerated hypereosinophilic neurons were present in HE-staining in both CA-groups. FluoroJade B-staining was negative in sham animals. In one week survivors 29±8 dying neurons (p=0.006) and in two week survivors 33±13 dying neurons (p= 0.016 vs sham, p=0.343 vs one week survivors) were detectable. Conclusions: Consistent damage in the medial CA1 region was present after 6 min VFCA in both survival time groups. Lesions seemed to be constant, with no significant differences between time points. Contrary to expectations, FluoroJade B-staining was still positive after two weeks of survival, suggesting that delayed cell death might go on for a longer time period than assumed so far.

Subfornical organ stimulation excites paraventricular neurons projecting to dorsal medulla

1984 ◽  
Vol 247 (6) ◽  
pp. R1088-R1092 ◽  
Author(s):  
A. V. Ferguson ◽  
T. A. Day ◽  
L. P. Renaud
Keyword(s):  
Electrical Stimulation ◽  
Functional Connectivity ◽  
Subfornical Organ ◽  
Sprague Dawley ◽  
Extracellular Recordings ◽  
Long Latency ◽  
Sprague Dawley Rats ◽  
Pressor Responses ◽  
Increased Activity ◽  
Dorsal Medulla

Electrical stimulation in the subfornical organ (SFO) of pentobarbital-anesthetized Sprague-Dawley rats was noted to influence the excitability of paraventricular nucleus (PVN) neurons antidromically identified as projecting to the dorsomedial medulla. Extracellular recordings indicated that 60% (n = 34) of these caudally projecting PVN neurons increased activity in response to single shock stimuli delivered to the SFO. Short-latency [30.0 +/- 2.7 (SE) ms] and long-latency (162.5 +/- 32.5 ms) responses were observed. The remaining neurons were either unaffected (38%) or inhibited (2%) by SFO stimulation. These data suggest functional connectivity between the SFO and the dorsomedial medulla. It is proposed that such a pathway may mediate pressor responses observed to follow electrical stimulation in the SFO.

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