Neural correlates of food anticipatory activity in mice subjected to once‐ or twice‐daily feeding periods

• Published in: The European journal of neuroscience Vol. 46; no. 7; pp. 2265 - 2275
• Main Authors: Rastogi, Ashutosh, Mintz, Eric M.
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01.10.2017
• Subjects: Activity patterns; Adaptation, Physiological; Animals; Anticipation, Psychological; circadian; Feeding; Feeding Behavior; Food; Fos protein; locomotor activity; Male; Mice; Mice, Inbred C57BL; Mus musculus; Neuronal Plasticity; Neuroplasticity; Oncogene Proteins v-fos - genetics; Oncogene Proteins v-fos - metabolism; Photoperiod; Photoperiods; Plasminogen Activators - genetics; Plasminogen Activators - metabolism; Rodents; Suprachiasmatic Nucleus Neurons - metabolism; Suprachiasmatic Nucleus Neurons - physiology; tissue‐type plasminogen activator; Mus musculus; circadian; locomotor activity; tissue-type plasminogen activator
• ISSN: 0953-816X; 1460-9568; 1460-9568
• DOI: 10.1111/ejn.13671

In rodents, restricted food access to a limited period each day at a predictable time results in the appearance of food anticipatory activity (FAA). Two shorter periods of food access each day can result in two FAA bouts. In this study, we examine FAA under 12:12 and 18:6 photoperiods in mice (Mus musculus) with one or two food access periods per day and measure the activation of the suprachiasmatic, dorsomedial and arcuate nuclei by assaying Fos protein expression, while making use of tissue‐type plasminogen activator knockout mice to assess the role of neural plasticity in adaptation to restricted feeding cycles. Long days were utilised to allow for temporal separation of two restricted feeding periods during the light phase. Mice fed twice per day generally divided FAA into two distinct bouts, with mice lacking tissue‐type plasminogen activator showing reduced FAA. Increases in Fos expression in response to one restricted feeding period per day were seen in the dorsomedial and arcuate nuclei in both 12:12 and 18:6 conditions, with an increase seen in the SCN in only the 12:12 condition. These increases were eliminated or reduced in the two feeding time conditions (done in 18:6 only). Both activity patterns and Fos expression differed for single restricted feeding times between 18:6 and 12:12 photoperiods. Fos activation was lower during RF in 18:6 than 12:12 across all three brain regions, a pattern not reflective of changes in FAA. These data suggest that involvement of these regions in FAA may be influenced by photoperiodic context. In rodents, restricted food access to a limited period each day at a predictable time results in the appearance of food anticipatory activity (FAA). Mice lacking tissue‐type plasminogen activator show reduced FAA in response to two restricted feeding periods per day, while increases in Fos expression in the DMH, ARC and SCN were reduced compared to a single restricted feeding period (filled circles denote tPA−/− mice). Locomotor activity and Fos expression also differ between 12:12 and 18:6 photoperiods.