Activating the subcortical ILSCm LP glutamatergic input pathway evoked similar short latency responses in the LA and elicited identical innate freezing responses.
Genetic experiments with Arabidopsis mutants have established roles for PHYA, PHYB, PHYD, PHYE, CRY1 and CRY2 in the clock input pathway [6] [8].
First, we showed that responses in NCM differ from those in the thalamo-recipient region, field L2 (on the principal input pathway to NCM).
Given the close link between light sensing and the circadian clock, it is tempting to speculate that they are also involved in the light input pathway.
This suggests that CRY1 acts as a signal transduction component downstream from PHYA in the low intensity light input pathway to the clock [15].
To determine, whether any other input pathway would yield a significantly higher proportion of synaptic KAR mediated current, we stimulated at the border of LII III mEC.
In order to assess whether little SAAS peptide is expressed in the light input pathway to the SCN, we examined little SAAS expression in retina and optic nerve.
If the photic input pathway to the SCN is altered in glaucoma, does this impact on the capacity for light entrainment by the circadian timing system?
The circadian clock located in the retina is unique since, in addition to containing all the components necessary for a complete 'circadian system' (i.e. a light input pathway, circadian oscillator, and multiple output pathways), it also serves as a direct input that delivers light information to the master clock in the suprachiasmatic nucleus (SCN) in the brain.
A simplified model of the clock comprises three basic components: an input pathway that senses light, a core oscillator that is the transcriptional machinery defining the rhythms, and output pathways that control various developmental and metabolic processes, resulting in the appropriate physiological adaptations to the day-night cycle (reviewed [1], [2]).
