PHOTOPERIODIC CONTROL OF SEASONAL BREEDING IN THE RAM: PARTICIPATION OF THE CRANIAL SYMPATHETIC NERVOUS SYSTEM

1979 ◽  
Vol 82 (1) ◽  
pp. 135-147 ◽  
Author(s):  
G. A. LINCOLN
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Reproductive Activity ◽  
Seasonal Breeding ◽  
Photoperiodic Control ◽  
Artificial Lighting ◽  
Lighting Conditions ◽  
Sympathetic Nervous ◽  
Cervical Ganglia ◽  
Short Days

SUMMARY Four mature Soay rams, cranially sympathectomized by removal of the superior cervical ganglia, were housed alongside four normal rams in controlled lighting conditions of alternating 16 week periods of short days of 8 h light: 16 h darkness (8L: 16D) and long days (16L: 8D). The changes in the concentration of FSH, LH, prolactin and testosterone in the plasma, the size of the testes, the intensity of the sexual flush and the sexual and aggressive behaviour of the animals were recorded. While the control rams were able to respond to the artificial lighting conditions with synchronized cycles of reproductive activity, the ganglionectomized animals failed to respond. The treated rams had well-developed testes and relatively high levels of gonadotrophins and testosterone in the blood throughout the experiment. It is concluded that the cranial sympathetic nervous system is involved in the photoperiodic control of seasonal breeding in the ram, probably through its role in the innervation of the pineal gland.

scholarly journals No Evidence of Neurogenesis in Adult Rat Sympathetic Ganglia Following Guanethidine-Induced Neuronal Loss

2019 ◽  
Vol 48 (1) ◽  
pp. 228-237 ◽  
Author(s):  
Karen M. Walters ◽  
Magalie Boucher ◽  
Germaine G. Boucher ◽  
Alan C. Opsahl ◽  
Peter R. Mouton ◽  
...  
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Sympathetic Neurons ◽  
Neuronal Loss ◽  
Sympathetic Ganglia ◽  
Adult Rat ◽  
Unbiased Stereology ◽  
Neuron Density ◽  
Sympathetic Nervous ◽  
Cervical Ganglia

The potential for neurogenesis in the cranial (superior) cervical ganglia (SCG) of the sympathetic nervous system was evaluated. Eleven consecutive daily doses of guanethidine (100 mg/kg/d) were administered intraperitoneally to rats in order to destroy postganglionic sympathetic neurons in SCG. Following the last dose, animals were allowed to recover 1, 3, or 6 months. Right and left SCG from guanethidine-treated and age-matched, vehicle-treated control rats were harvested for histopathologic, morphometric, and stereologic evaluations. Both morphometric and stereologic evaluations confirmed neuron loss following guanethidine treatment. Morphometric analysis revealed a 50% to 60% lower number of tyrosine hydroxylase (TH)-positive neurons per unit area of SCG at both 3 and 6 months of recovery, compared to ganglia of age-matched controls, with no evidence of restoration of neuron density between 3 and 6 months. Reductions in TH-positive neurons following guanethidine treatment were corroborated by unbiased stereology of total hematoxylin and eosin-stained neuron numbers in SCG. Stereologic analyses revealed that total neuron counts were lower by 37% at 3 months of recovery when compared to age-matched vehicle controls, again with no obvious restoration between 3 and 6 months. Thus, no evidence was found that postganglionic neurons of the sympathetic nervous system in the adult rat have a neurogenic capacity.

Thyroid hormone-catecholamine interrelationships during exposure to cold

1981 ◽  
Vol 97 (1) ◽  
pp. 91-97 ◽  
Author(s):  
H. Storm ◽  
C. van Hardeveld ◽  
A. A. H. Kassenaar
Keyword(s):  
Nervous System ◽  
Plasma Concentration ◽  
Thyroid Hormone ◽  
Sympathetic Nervous System ◽  
Plasma Levels ◽  
Surgical Procedure ◽  
Exposure To Cold ◽  
Basal Plasma ◽  
Sympathetic Nervous

Abstract. Basal plasma levels for adrenalin (A), noradrenalin (NA), l-triiodothyronine (T3), and l-thyroxine (T4) were determined in rats with a chronically inserted catheter. The experiments described in this report were started 3 days after the surgical procedure when T3 and T4 levels had returned to normal. Basal levels for the catecholamines were reached already 4 h after the operation. The T3/T4 ratio in plasma was significantly increased after 3, 7, and 14 days in rats kept at 4°C and the same holds for the iodide in the 24-h urine after 7 and 14 days at 4°C. The venous NA plasma concentration was increased 6- to 12-fold during the same period of exposure to cold, whereas the A concentration remained at the basal level. During infusion of NA at 23°C the T3/T4 ratio in plasma was significantly increased after 7 days compared to pair-fed controls, and the same holds for the iodide excretion in the 24-h urine. This paper presents further evidence for a role of the sympathetic nervous system on T4 metabolism in rats at resting conditions.

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