Journal ArticleDOI
Timed daily injections of neurotransmitter precursors alter the gonad and body weights of spotted munia, Lonchura punctulata, maintained under short daily photoperiods
C. M. Chaturvedi,S. K. Prasad +1 more
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The results indicate that interaction between these two systems does not produce any pharmacological effect but actually affects the seasonality of the birds, as indicated by the different gonadal and metabolic conditions that followed differently timed daily injections of drugs that influence serotonergic and dopaminergic activities.Abstract:
The present study was designed to examine the role of circadian organization in the control of seasonality in the seasonally breeding spotted munia, Lonchura punctulata, which does not utilize photoperiod to time its reproduction under natural day-length conditions.
Daily injections of L-dihydroxyphenylalanine (L-DOPA, precursor of dopamine) given 12 hr and 8 hr after administration of 5-hydroxytryptophan (5-HTP, precursor of serotonin) alter the gonadal and body-weight responses of the spotted munia, when it is maintained under short-day conditions (LD 6:18). The 12-hr interval was stimulatory and the 8-hr interval was inhibitory for both gonadal and body-weight responses while other intervals (0, 4, and 16 hr) had no effect. A 20-hr interval was stimulatory only for gonadal growth and had no effect on body weight.
These findings support the suggestion that the endogenous seasonal mechanism is determined by circadian organization (i.e., by changes in the phase relationships of two neural oscillations and their many other circadian expressions). The results also indicate that interaction between these two systems does not produce any pharmacological effect but actually affects the seasonality of the birds, as indicated by the different gonadal and metabolic conditions that followed differently timed daily injections of drugs that influence serotonergic and dopaminergic activities. Furthermore, the mechanism of regulation of seasonality seems to be similar in species that do and do not utilize day length as the primary regulator with which to time their seasonal reproductive and metabolic cycles.read more
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Journal ArticleDOI
Temporal synergism of neurotransmitters (serotonin and dopamine) affects testicular development in mice.
TL;DR: It is concluded that normal somatic and gonadal growth of pre-puberal mice may be suppressed with an 8-hr phase relation of circadian serotonergic and dopaminergic oscillations, which accelerated the rate of gonadal maturation and led to more or less similar gonadal development as in the control mice.
Journal ArticleDOI
Effect of temporal synergism of neural oscillations on photorefractoriness in Japanese quail (Coturnix coturnix japonica).
TL;DR: The findings indicate that 12-hr temporal interaction of 5-HTP and L-DOPA administration maintained reproductive system in stimulated condition and prevented reproductive regression in photorefractory quail, but did not prevent the onset of scotosensitivity.
Journal ArticleDOI
Nesfatin-1: Localization and expression in avian gonads and its modulation by temporal phase relation of neural oscillations in female Japanese quail, Coturnix coturnix japonica
TL;DR: Present avian study, first of its kind, suggests the role of nesfatin-1 in reproductive regulation possibly via appetite control and energy balance in female Japanese quail and needs to be investigated further in relation to food intake.
Journal ArticleDOI
Suppression of annual testicular development in Indian Palm Squirrel, Funambulus pennanti by 8 hr temporal relationship of serotonin and dopamine precursor drugs
TL;DR: Results indicate that induced suppression of gonadal function in a fashion similar to seasonal regression leading to non-breeding condition is the consequence of specific phase relationship (8 hr) between serotonergic and dopaminergic activities and not due to Serotonin or dopamine alone.
Journal ArticleDOI
Effects of simulated hypo- and hyper-reproductive conditions on the characteristics of circadian rhythm in hypothalamic concentration of serotonin and dopamine and in plasma levels of thyroxine, triiodothyronine, and testosterone in Japanese quail, Coturnix coturnix japonica.
Pankaj Kumar,Atanu Kumar Pati,Jag Mohan,K.V.H. Sastry,Jagbir Singh Tyagi,Chandra Mohini Chaturvedi +5 more
TL;DR: It is suggested that administration of 5‐HTP and L‐DOPA at specific time interval and variation in pineal functions that modulate reproductive responses also alter the circadian pattern (acrophase and amplitude) of hypothalamic serotonin and dopamine, maintaining a specific phase relation between these cycles and breeding status.
References
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Book
Computational Handbook of Statistics
James L. Bruning,B. L. Kintz +1 more
TL;DR: In this paper, the authors present an analysis of correlation and correlation coefficients for the Mann-Whitney Test, the Newman-Keuls' and Tukey Mulitple-Comparison Tests, and the Signed-Pairs, Signed-Ranks Test.
Journal ArticleDOI
Photorefractoriness in birds and comparison with mammals
Journal ArticleDOI
Light and other environmental factors affecting avian reproduction.
Donald S. Farner,B. K. Follett +1 more
Journal ArticleDOI
Circadian rhythmicity in photoperiodically induced gonadotrophin release and gonadal growth in the quail.
B. K. Follett,P. J. Sharp +1 more
TL;DR: There is now good evidence available to support Bünning's hypothesis in plants, and in at least four species of finches where the photoperiodic induction of testicular growth also relies on a circadian rhythm.
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