“Centro Interdisciplinario de Neurociencia de Valparaíso”.
Research Area: Biological clocks.
Neurogenetics of Behavior and Development in Drosophila melanogaster laboratory, Professor John Ewer
Ph.D. in Sciences (Mention in Neuroscience) Universidad de Valparaíso, Chile (2015).
Graduate in Biochemist, Universidad Católica de Valparaíso, Chile (2007)
E-mail: angelina.palacios at cinv.cl, angelinapm8107 at gmail.com
Fax: (56)-(32)-250 1111
Address: Centro Interdisciplinario de Neurociencia de Valparaíso.
Facultad de Ciencias, Universidad de Valparaíso.
Gran Bretaña 1111. Playa Ancha. Valparaíso. Chile.
In animals the circadian clock imposes a daily rhythm on behavior and physiology. In the fruit fly, Drosophila melanogaster, the circadian clock restricts the time of emergence of the adult fly (eclosion) to the early part of the day. The emergence of the adult fly is the culmination of the developmental process of metamorphosis, which is controlled by the steroid molting hormone, 20-hydroxy-ecdysone (20E). The prothoracic gland (PG) is a peripheral gland that produces ecdysone (the 20E precursor). The PG also contains a circadian pacemaker, which, together with the central pacemaker in the brain, controls the timing of adult emergence.
During my Doctoral thesis proyect I demonstrated that intracelular Ca2+ and cyclic-AMP levels are varied in PG during the course of the day under both light/dark (LD) and dark/dark (DD) conditions. In addition, I found that genetic manipulations that produce sustained increases and decreases in Ca2+ and cAMP levels in the PG caused, respectively, a shortening and a lengthening of the period of eclosion compared to that of controls. I also found that similar manipulations directed at the central clock neurons affected, in similar manner, the periodicity of adult locomotor activity under free-running conditions (DD). These results indicate that the levels of these second messengers can alter the functioning of the clock itself, suggesting that Ca2+/cAMP could be part of a homeostatic mechanism through which physiological stimuli external to the circadian clock can alter its period. These results are relevant for understanding how clocks and an organism’s physiological state are coordinated to produce a unified internal time.
Currently, I am investigating how the clock neurons or “master clock” localized in the central nervous system are coupled to others peripheral pacemakers to produce a daily rhythm of emergence of the fly. These questions are general interest, and, in particular are relevant to human welfare, where proper coordination between central nervous system clock and peripheral clocks is essential for optimum performance, health, and well-being.
Isaac E. García, Jaime Maripillán, Oscar Jara, Ricardo Ceriani, Angelina Palacios-Muñoz, Jayalakshmi Ramachandran, Pablo Olivero, Tomás Pérez-Acle, Carlos González León, Juan Carlos Sáez, Jorge E. Contreras, Agustín D. Martínez. (2015). Keratitis-Ichthyosis-Deafness syndrome-associated Cx26 mutants produce non-functional gap junctions but hyperactive hemichannels when co-expressed with wild type Cx43. Journal of Investigative Dermatology. doi:10.1038/jid.2015.20
Palacios-Muñoz A, Escobar MJ, Vielma A, Araya J, Astudillo A, Valdivia G, García IE, Hurtado J, Schmachtenberg O, Martínez AD and Palacios AG. (2014). Role of connexin channels in the retinal light response of a diurnal rodent. Front. Cell. Neurosci. 8:249. doi: 10.3389/fncel.2014.00249