Morphological features of physiologically identified hypothalamic neurons as revealed by intracellular marking

SummaryIn the in vitro slice preparation intracellular recordings and injections of procion yellow (PY) were made in neurons of the hypothalamus. Of these neurons, one medial preoptic-anterior hypothalamus (MPO-AH) and four arcuate-ventromedial hypothalamus (ARC-VM) neurons were driven by electrical stimulation of the median eminence area (ME). Two other MPO-AH and five other ARC-VM neurons were driven by stimulation of the stria terminalis (ST). On the basis of the PY injections two morphologically distinct cell types were delineated: a larger multipolar cell type with a polygonal perikaryon was found with equal frequency in the MPO-AH and the ARC-VM. A smaller fusiform cell type was encountered mainly in the ARC-VM. On the secondary dendrites of both cell types spine-like appendages were seldom seen, but dendritic swellings were common. Some of the dendrites projected to capillaries in both areas and presumably contacted them. The axons were usually tortuous and could only be traced a short distance.

[1]  J. Szentágothai.  The Parvicellular Neurosecretory System , 1964 .

[2]  O. E. Millhouse.  The organization of the ventromedial hypothalamic nucleus. , 1973, Brain research.

[3]  R. L. Moss,et al.  The specificity of the response of preoptic-septal area neurons to estrogen: 17α-estradiol versus 17β-estradiol and the response of extrahypothalamic neurons , 1977, Experimental Brain Research.

[4]  P. Field.  A quantitative ultrastructural analysis of the distribution of amygdaloid fibres in the preoptic area and the ventromedial hypothalamic nucleus , 1972, Experimental Brain Research.

[5]  E. R. Kandel,et al.  Electrical Properties of Hypothalamic Neuroendocrine Cells , 1964, The Journal of general physiology.

[6]  Cross Ba.  Unit responses in the hypothalamus. , 1973 .

[7]  R. L. Moss,et al.  Chemosensitivity of hypophysiotropic neurons to the microelectrophoresis of biogenic amines , 1978, Brain Research.

[8]  A. Weindl,et al.  Peptide Neurohormones and Circumventricular Organs in the Pigeon1 , 1981 .

[9]  R. L. Moss,et al.  The effect of ovariectomy on the responsiveness of preoptic-septal neurons to microelectrophoresed estrogen. , 1978, Neuroendocrinology.

[10]  L. Renaud.  Influence of amygdala stimulation on the activity of identified tuberoinfundibular neurones in the rat hypothalamus. , 1976, The Journal of physiology.

[11]  K. Yagi,et al.  Neurosecretory Cell: Capable of Conducting Impulse in Rats , 1966, Science.

[12]  J. N. Hayward.  Functional and morphological aspects of hypothalamic neurons. , 1977, Physiological reviews.

[13]  M. Réthelyi,et al.  Dendritic arborization and axon trajectory of neurons in the hypothalamic arcuate nucleus of the rat , 1977, Experimental Brain Research.

[14]  R. Llinás,et al.  Electrophysiological properties of dendrites and somata in alligator Purkinje cells. , 1971, Journal of neurophysiology.

[15]  R. L. Moss,et al.  The effects of microelectrophoretically applied estrogen, cortisol and acetylcholine on medial preoptic-septal unit activity throughout the estrous cycle of the female rat , 1977, Experimental Brain Research.

[16]  J. N. Hayward.  Physiological and morphological identification of hypothalamic magnocellular neuroendocrine cells in goldfish preoptic nucleus * , 1974, The Journal of physiology.

[17]  P. Reier,et al.  The ultrastructure of the developing medial preoptic nucleus in the postnatal rat , 1977, Brain Research.

[18]  R. Schaumberg,et al.  Transynaptic transport of procion yellow in the central nervous system , 1979, Experimental Brain Research.

[19]  E. Kravitz,et al.  Neuronal Geometry: Determination with a Technique of Intracellular Dye Injecion , 1968, Science.

[20]  M. Pickford.  HYPOTHALAMIC CONTROL OF THE ANTERIOR PITUITARY , 1963 .

[21]  R. L. Moss,et al.  Hypothalamic polypeptide releasing hormones: Modifiers of neuronal activity , 1978, Neuropharmacology.

[22]  E. Rieske,et al.  Intradendritic transport to postsynaptic sites. , 1973, Brain research.

[23]  R. Dyer.  An electrophysiological dissection of the hypothalamic regions which regulate the pre‐ovulatory secretion of luteinizing hormone in the rat , 1973, The Journal of physiology.

[24]  W. Zieglgänsberger,et al.  Interneuronal movement of procion yellow in cat spinal neurones , 2004, Experimental Brain Research.