[Functional organization of a photoperiodic brain system]

Area of Science:

• Neuroscience
• Chronobiology
• Endocrinology

Background:

• The neurofunctional system perceives photoperiod, acting as a crucial part of the organism's chronoperiodic system.
• It transfers environmental light cues (Zeitgeber) to peripheral tissues, synchronizing biological rhythms and adaptation mechanisms.

Purpose of the Study:

• To review the mechanisms of photoperiodic information conduction.
• To elucidate the roles of the suprachiasmatic nuclei and pineal gland in photoperiodic signaling.
• To examine the characteristics of circadian and circannual aspects of the photoperiodic system.

Main Methods:

• Literature review focusing on neurofunctional and neuroendocrinal pathways.
• Analysis of the roles of key brain structures like the suprachiasmatic nuclei and pineal gland.
• Investigation of humoral elements, including melatonin and adenosine, in photoperiodic information transfer.

Main Results:

• The suprachiasmatic nuclei are central to endogenous rhythm oscillation, while the pineal gland acts as a neuroendocrinal transducer.
• Melatonin, the hormone of darkness, and adenosine are implicated in conveying photoperiodic information.
• The septohippocampal system is identified as a key center for storing photoperiodic information.

Conclusions:

• The photoperiodic system is vital for synchronizing physiological functions and adapting to environmental changes.
• Understanding the neurobiological basis of photoperiodism, including the roles of melatonin and adenosine, is crucial.
• The septohippocampal system's role in memory suggests its involvement in retaining photoperiodic information.