Hypothalamus mediobasal

Anxiolytic Rat preoptic area/mediobasal hypothalamus progesterone Markers for anxiolytic response [22]... 

Meister, B. and Hokfelt, T. (1988) Peptide- and transmitter-containing neurons in the mediobasal hypothalamus and their relation to GABAergic systems possible roles in control of prolactin and growth hormone secretion. Synapse 2, 585-605. 

In adult rats, perikarya of TIDA neurons, originally described as comprising the A12 cell group (Dahlstrom and Fuxe, 1964), are distributed throughout the rostrocaudal extent of the ARC and adjacent periventricular nucleus of the mediobasal hypothalamus. Two populations of TH-containing neurons have been identified based on their neurochemical... 

Prior to postnatal day 21, the characteristics of the TIDA neurons in dwarf mice cannot be distinguished from those in the normal littermate controls. That is, the DA content in the mediobasal hypothalamus and the number of TH-positive perikarya are the same in dwarf and normal mice. After 21 days of life, TIDA neurons in the dwarf mice regress such that their number at 60 days of age is less than it is at 21 days. This could represent the... 

The rapid (i.e. less than 4 h) activation of TH in the median eminence by prolactin that constitutes the tonic component of prolactin stimulation does not require protein synthesis, but is probably associated with effects on the catalytic properties of this enzyme. Pasqualini and coworkers (1994) demonstrated in vitro that prolactin acts directly on TH in the mediobasal hypothalamus to trigger the phosphorylation of this enzyme. This effect, possibly mediated by protein kinase C, makes the enzyme less susceptible to inhibition by newly synthesized DA. That is, prolactin-induced short-term activation of TH results from the removal of end-product inhibition of the enzyme. Conversely, the acute reduction in TH activity measured in vitro in median eminence removed from rats 4 h after administration of bromocriptine is prevented by the coadministration of prolactin (Arbogast and Voogt, 1995). This can also be prevented by an inhibitor of phosphoprotein phosphatases, suggesting that rapid suppression of TH activity secondary to the bromocriptine-induced hypoprolactinemia may also result from dephosphorylation of the enzyme. 

Whether neurotensin acts directly at NTRi receptors on TIDA neurons is not clear. The presence of dense neurotensin binding sites located within the mediobasal hypothalamus (Goedert et al., 1985 Meister et al., 1989) and the observation that single unit activity of approximately 70% of all DM-ARC neurons is stimulated by neurotensin in vitro suggest a localized action on (or near) TIDA neurons (Lin and Pan, 1993). Moreover, the presence of synaptic connections between neurotensin-IR and TH-IR neurons in the DM-ARC is consistent with a direct action of neurotensin on TIDA neurons (Marcos et al., 1996a). On the other hand, TIDA neurons do not normally express appreciable amounts of neurotensin receptor mRNA like mesotelencephalic DA neurons... 

Balan IS, Ugrumov MV, Calas A, Mailly P, Krieger M, Thibault J (2000) Tyrosine Hydroxylase-expressing and/ or aromatic L-amino acid decarboxylase-expressing neurons in the mediobasal hypothalamus of perinatal rats differentiation and sexual dimorphism. J Comp Neurol 25 167-176. 

Kapoor R, Willoughby JO (1990) Activation of opioid receptors in the mediobasal hypothalamus stimulates prolactin secretion in the concious rat. J Neuroendocrinol 2 347-350. 

Marcos P, Corio M, Dubourg P, Tramu G (1996a) Reciprocal synaptic connections between neurotensin- and tyrosine hydroxylase-immunoreactive neurons in the mediobasal hypothalamus of the guinea pig. Brain Res 775 63-70. 

Meister B, Ceccatelli S, Hokfelt T, Anden NE, Anden M, Theodorsson E (1989) Neurotransmitters, neuropeptides and binding sites in the rat mediobasal hypothalamus effects of monosodium glutamate (MSG) lesions. Exp Brain Res 76 343-368. 

Reymond MJ, Arita J, Dudley CA, Moss RL, Porter JC (1984) Dopaminergic neurons in the mediobasal hypothalamus of old rats evidence for a decreased affinity of tyrosine hydroxylase for substrate and cofactor. Brain Res 304 215-223. 

Timmerman W, Deinum ME, Poelman RT, Westerink BHC, Schuiling GA (1994) Characterization of the DA-ergic system in the mediobasal hypothalamus a new approach to simultaneously monitor the release of DA from the TIDA neurons and the PRL secretion from the adenohypophysis in awake rats. Brain Res... 

Ascorbic acid stimulates the release of acetylcholine and noradrenaline from isolated synaptic vesicles (Kuo et aL, 1979). The release mechanisms of acetylcholine are more sensitive to ascorbic acid than those of noradrenaline (2-2.5 jlM vs. 20 xM of EC50 for ascorbic acid). Ascorbic acid also enhances the release of vasoactive intestinal polypeptide from neuroblastoma (Brick et aL, 1985) and that of luteinizing hormone-releasing hormone (LHRH) from the mediobasal hypothalamus in vitro (Miller and Cicero, 1986). The latter effect may not be due to the reductive property of ascorbic acid, since another reducing agent, sodium metabisulfite, did not induce the release of LHRH. 

Miller, B. T, and Cicero, T J., 1986, Ascorbic acid enhances the release of luteinizing hormonereleasing hormone from the mediobasal hypothalamus in vitro. Life Sci. 39 2447-2454. 

Pich EM, Koob GJ, HeiUg M, Menzaghi F, Vale W, Weiss F. Corticotropin-releasing factor release from the mediobasal hypothalamus of the rat as measured by microdialysis. Neurosci 1993 55 695—707. 

---