Biomaterial Database

Effects of photoperiod on estrogen receptor, tyrosine hydroxylase, neuropeptide Y, and beta-endorphin immunoreactivity in the ewe hypothalamus. 1997

D C Skinner, and A E Herbison

Laboratory of Neuroendocrinology, The Babraham Institute, Cambridge, United Kingdom.

The neural components underlying the influence of photoperiod upon reproductive functioning are poorly understood. In this study, we have used immunocytochemistry to examine whether changes in photoperiod may influence specific neuronal cell populations implicated in mediating gonadal steroid feedback actions on GnRH neurons. Short day (SD) exposed ewes in the midluteal stage of the estrous cycle and long day (LD) anestrous ewes were perfused in pairs and hypothalamic brain sections immunostained for tyrosine hydroxylase (TH), neuropeptide Y (NPY), beta-endorphin (betaE), and the estrogen receptor (ER). The number of ER-immunoreactive cells detected within the preoptic area, but not the hypothalamus, was approximately 20% higher (P < 0.05) in LD ewes compared with SD animals. The numbers of TH-immunoreactive neurons comprising the A12, A14, and A15 cell groups were not different between LD and SD ewes, and the percentage of A12 (approximately 15%) and A14 (approximately 25%) neurons expressing ERs was similarly unaffected by photoperiod. The number of betaE neurons detected in the arcuate nucleus was 50% lower (P < 0.05) in SD vs. LD ewes, whereas NPY-immunoreactive cell numbers in the median eminence were 300% higher (P < 0.05). Approximately 3% of NPY neurons in the median eminence, and 10% in the arcuate nucleus, expressed ER immunoreactivity in a photoperiod-independent manner. These studies indicate that changes in photoperiod may regulate ER expression within the preoptic area and suggest that hypothalamic NPY and betaE neurons are involved in the seasonal regulation of reproductive activity in the ewe.

UI	MeSH Term	Description	Entries
D007031	Hypothalamus	Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.	Lamina Terminalis,Preoptico-Hypothalamic Area,Area, Preoptico-Hypothalamic,Areas, Preoptico-Hypothalamic,Preoptico Hypothalamic Area,Preoptico-Hypothalamic Areas
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D009478	Neuropeptide Y	A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.	Neuropeptide Y-Like Immunoreactive Peptide,Neuropeptide Tyrosine,Neuropeptide Y Like Immunoreactive Peptide,Tyrosine, Neuropeptide
D009928	Organ Specificity	Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.	Tissue Specificity,Organ Specificities,Specificities, Organ,Specificities, Tissue,Specificity, Organ,Specificity, Tissue,Tissue Specificities
D011301	Preoptic Area	Region of hypothalamus between the ANTERIOR COMMISSURE and OPTIC CHIASM.	Area Preoptica,Lateral Preoptic Area,Medial Preoptic Area,Preoptic Nuclei,Area Preopticas,Area, Lateral Preoptic,Area, Medial Preoptic,Area, Preoptic,Areas, Lateral Preoptic,Areas, Medial Preoptic,Areas, Preoptic,Lateral Preoptic Areas,Medial Preoptic Areas,Nuclei, Preoptic,Nucleus, Preoptic,Preoptic Area, Lateral,Preoptic Area, Medial,Preoptic Areas,Preoptic Areas, Lateral,Preoptic Areas, Medial,Preoptic Nucleus,Preoptica, Area,Preopticas, Area
D011960	Receptors, Estrogen	Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.	Estrogen Receptor,Estrogen Receptors,Estrogen Nuclear Receptor,Estrogen Receptor Type I,Estrogen Receptor Type II,Estrogen Receptors Type I,Estrogen Receptors Type II,Receptor, Estrogen Nuclear,Receptors, Estrogen, Type I,Receptors, Estrogen, Type II,Nuclear Receptor, Estrogen,Receptor, Estrogen
D002552	Cerebral Ventricles	Four CSF-filled (see CEREBROSPINAL FLUID) cavities within the cerebral hemispheres (LATERAL VENTRICLES), in the midline (THIRD VENTRICLE) and within the PONS and MEDULLA OBLONGATA (FOURTH VENTRICLE).	Foramen of Monro,Cerebral Ventricular System,Cerebral Ventricle,Cerebral Ventricular Systems,Monro Foramen,System, Cerebral Ventricular,Systems, Cerebral Ventricular,Ventricle, Cerebral,Ventricles, Cerebral,Ventricular System, Cerebral,Ventricular Systems, Cerebral
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms