Metabolic activation of amygdala, lateral septum and accumbens circuits during food anticipatory behavior.
When food is restricted to a brief fixed period every day, animals show an increase in temperature, corticosterone concentration and locomotor activity for 2-3h before feeding time, termed food anticipatory activity. Mechanisms and neuroanatomical circuits responsible for food anticipatory activity remain unclear, and may involve both oscillators and networks related to temporal conditioning. Rabbit pups are nursed once-a-day so they represent a natural model of circadian food anticipatory activity. Food anticipatory behavior in pups may be associated with neural circuits that temporally anticipate feeding, while the nursing event may produce consummatory effects. Therefore, we used New Zealand white rabbit pups entrained to circadian feeding to investigate the hypothesis that structures related to reward expectation and conditioned emotional responses would show a metabolic rhythm anticipatory of the nursing event, different from that shown by structures related to reward delivery. Quantitative cytochrome oxidase histochemistry was used to measure regional brain metabolic activity at eight different times during the day. We found that neural metabolism peaked before nursing, during food anticipatory behavior, in nuclei of the extended amygdala (basolateral, medial and central nuclei, bed nucleus of the stria terminalis), lateral septum and accumbens core. After pups were fed, however, maximal metabolic activity was expressed in the accumbens shell, caudate, putamen and cortical amygdala. Neural and behavioral activation persisted when animals were fasted by two cycles, at the time of expected nursing. These findings suggest that metabolic activation of amygdala-septal-accumbens circuits involved in temporal conditioning may contribute to food anticipatory activity.
Programa de Doctorado en Ciencias Biomédicas, Universidad Veracruzana, Xalapa, Veracruz 91190, Mexico. Electronic address: dolivormz@gmail.com.
Diana
D
Olivo
Centro de Investigaciones Biomédicas, Universidad Veracruzana, Xalapa, Veracruz 91190, Mexico. Electronic address: mcaba@uv.mx.
Mario
M
Caba
Department of Psychology and Institute for Neuroscience, The University of Texas at Austin, Austin, TX 78712, USA. Electronic address: gonzalezlima@utexas.edu.
Francisco
F
Gonzalez-Lima
Laboratorio de Neurofarmacología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz 91190, Mexico. Electronic address: juarodriguez@uv.mx.
Juan F
JF
Rodríguez-Landa
Laboratorio de Investigación Genómica y Fisiológica, Facultad de Nutrición, Médicos y odontólogos s/n, Col. Unidad del Bosque, 91010, Universidad Veracruzana, Xalapa, Veracruz, Mexico. Electronic address: alecorona@uv.mx.
Aleph A
AA
Corona-Morales
D065767:Activation, Metabolic / Q000235:genetics / Q000502:physiology*; D000367:Age Factors; D000679:Amygdala / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D002940:Circadian Rhythm / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D004558:Electric Stimulation; D003576:Electron Transport Complex IV / Q000378:metabolism; D005215:Fasting; D005502:Food; D008124:Locomotion / Q000502:physiology; D009042:Motivation / Q000235:genetics / Q000502:physiology*; D009714:Nucleus Accumbens / Q000378:metabolism*; D011817:Rabbits; D012201:Reward; D020665:Septum of Brain / Q000378:metabolism*
D003576:Electron Transport Complex IV
Circadian rhythm ontogeny; Conditioned emotional behavior; Cytochrome oxidase histochemistry; Food anticipatory activity; Reward expectation