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G Erhart

Publications and source records attributed to G Erhart.

16 recordsLinked to original sources

Hypothalamo-neurohypophysial system in hagfish: localization of neurophysin-, arg-vasopressin- and oxytocin-like immunoreactivity.

Serial paraffin sections of hagfish brain (Eptatretus burgeri) were immunocytochemically examined for porcine neurophysin (NEU), arg-vasopressin (AVP) and oxytocin (OT). A big number of NEU-immunoreactive nerve cells were visible in the frontal part of the ventromedial hypothalamus in close vicinity of the third ventricle. These cells were bipolar in most cases and sometimes additionally stained for AVP but not for OT. NEU-reactive neurons extended axons to the median eminence and the posterior lobe of the pituitary which also contained AVP or OT-like immunoreactivity. Immunostaining outside the hypothalamus could not be observed. It is likely that there exists a mammalian-like oxytocinergic and a vasopressinergic hypothalamo-neurohypophysial system in hagfish, despite the large differences in levels of organization.

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FMRF-amide-like immunoreactivity in brain and pituitary of the hagfish Eptatretus burgeri (Cyclostomata).

Paraffin sections of brain and pituitary of the hagfish Eptatretus burgeri were immunostained with an antiserum to FMRF-amide. Immunoreactivity was visible in a large number of neurons in the posterior part of the ventromedial hypothalamus and in long neuronal processes extending cranially from the hypothalamus to the olfactory system and caudally to the medulla oblongata. FMRF-amide-like immunoreactivity was also found in cells of the adenohypophysis. These observations suggest that the hagfish possesses a brain FMRF-amide-like transmitter system and pituitary cells containing FMRF-amide-like material. Antisera to ACTH, alpha-MSH and pancreatic polypeptide gave no immunoreaction in hagfish brain or pituitary.

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Cell types in the adenohypophysis of the hagfish, Myxine glutinosa (Cyclostomata).

The anterior pituitary of the Atlantic hagfish, Myxine glutinosa, was investigated by transmission electron microscopy. The cells of the adenohypophysis are arranged in follicles surrounded by connective tissue. Five cell types containing granules and one agranular cell type were identified. At the present state of the study the function of these cells remains open to discussion.

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