Recently, we have discovered that a brain substance which binds to anti-prolactin immune serum increases the estrogen-dependent behavior, lordosis, in female rats, raising the possibility that part of the nerual action of estrogen is mediated through cells containing this prolactin-like substance. The proposed research focuses primarily on the hypothalamus to midbrain connection, which is critically involved in mediating estrogen-dependent effects on lordosis and which contains immunoreactive prolactin. Specifically, we will perform behavioral experiments in female rats to explore further the role of a prolactin-like substance in lordosis. We will provide a comprehensive description of the distribution of immunoreactive prolactin in male and female rat brains, at the light microscopic level. the apparent molecular weight and isoelectric point of the prolactin-like substance will be determined by electrophoresis of immunoprecipitated brain homogenates from intact and hypophysectomized rats. We will study the possible effects of gonadal hormones on the content of prolactin-like substance in the brain by exploring whether hormones alter the amount of immunoreactive prolactin in cell bodies and fibers. By combining immunocytochemistry with autoradiography, we will determine whether cells producing the prolactin-like substance also concentrate estrogen. We have preliminary evidence that the prolactin gene is expressed in the brain. Due to the substantial amount of information available on the prolactin gene, the neuronal system containing immunoreactive prolactin may become one of the best characterized brain pathways. These studies should provide new knowledge of the mechanisms by which gonadal steroids act on the brain, the long-term objective of this research. In humans, steroid hormone action on the brain regulates fertility and reproductive senescence and can exacerbate several neurological problems, such as chorea, Parkinsonism and epilepsy.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS024148-03
Application #
3408428
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1986-04-01
Project End
1992-03-31
Budget Start
1988-04-01
Budget End
1989-03-31
Support Year
3
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Tulane University
Department
Type
Schools of Medicine
DUNS #
City
New Orleans
State
LA
Country
United States
Zip Code
70118
Heimer, L; Alheid, G F; de Olmos, J S et al. (1997) The accumbens: beyond the core-shell dichotomy. J Neuropsychiatry Clin Neurosci 9:354-81
Lucas, L R; Harlan, R E (1995) Cholinergic regulation of tachykinin- and enkephalin-gene expression in the rat striatum. Brain Res Mol Brain Res 30:181-95
Song, D D; Harlan, R E (1994) Genesis and migration patterns of neurons forming the patch and matrix compartments of the rat striatum. Brain Res Dev Brain Res 83:233-45
Lucas, L R; Mize, R R; Harlan, R E (1994) Semiquantitative analysis of in-situ hybridization results using IMAGE software: a rapid method for counting reduced silver grains over mRNA-positive cells. J Neurosci Methods 52:101-9
Mize, R R; Thouron, C; Lucas, L et al. (1994) Semiautomatic image analysis for grain counting in in situ hybridization experiments. Neuroimage 1:163-72
Zhang, L; Harlan, R E (1994) Ontogeny of the distribution of tachykinins in rat cerebral cortex: immunocytochemistry and in situ hybridization histochemistry. Brain Res Dev Brain Res 77:23-36
Song, D D; Harlan, R E (1994) The development of enkephalin and substance P neurons in the basal ganglia: insights into neostriatal compartments and the extended amygdala. Brain Res Dev Brain Res 83:247-61
Song, D D; Harlan, R E (1993) Ontogeny of the proenkephalin system in the rat corpus striatum: its relationship to dopaminergic innervation and transient compartmental expression. Neuroscience 52:883-909
Huang, X; Harlan, R E (1993) Absence of androgen receptors in LHRH immunoreactive neurons. Brain Res 624:309-11
Garcia, M M; Cusick, C G; Harlan, R E (1993) Protein kinase C-delta in rat brain: association with sensory neuronal hierarchies. J Comp Neurol 331:375-88

Showing the most recent 10 out of 25 publications