Robert Baker

Robert_BakerProfessor, Department of Neuroscience & Physiology

550 First Avenue
Room 458 Medical Science Building
New York, NY 10016
Phone: 212-263-5402, 212-263-8894
Fax: 212-689-9060

Research Summary:

Neuroethology of hindbrain and cerebellar circuits in vertebrates.

The long term goal of my research has been to provide a better understanding of the diverse hindbrain circuits and behaviors controlling eye movements, locomotion, swimming and vocalization by integrating molecular, genetic and developmental work in zebrafish centered on homeotic (Hox) paralog group 3 and 4 genes with neuronal signaling and computational approaches in numerous other fish species. Exactly where individual Hox proteins are expressed and transported is of great significance for understanding how individual genes and experience influence behavior. Using time lapse, three dimensional imaging microscopy in transgenic fluorescent zebrafish along with markers specific to motor, precerebellar and reticular neurons we showed roles for the same Hox gene in hindbrain neural circuits extending from involuntary through voluntary motor function including cerebellar pathways. Maintained homeotic gene expression suggests that both experience and growth-related requirements are continuously integrated throughout growth into new neurons entering behaviorally specific circuits. Experimentally, these observations fit well with the genetic idea of mosaic pleiotropism as extensively discussed in the developmental and evolutionary literature. Our findings, therefore, suggest novel, unconventional roles for homeotic genes in the building of hindbrain neuronal circuits during the acquisition of function. Fascinatingly, these newly observed genetic traits also offer a robust modifiable transcriptional site for the evolution of neuronal circuits. Hence, the long-term goal of my research is to identify discrete enhancer modules essential for defining the operation of specific hindbrain neurons and circuits contributing to oculomotor signal processing, particularly those that utilize the cerebellum for learning and memory. Since the hindbrain compartments in all vertebrates exhibit highly conserved genetic and developmental profiles, the research is of significance for an experimental and theoretical framework for oculomotor-related behaviors in all species.

Selected Publications:

  • Debowy, O. and Baker, R. (2011). Encoding of eye position in the goldfish horizontal oculomotor neural integrator. J Neurophysiol. 105: 896-909, 2011.

  • Chagnaud, B. P., Baker, R., and Bass A. H. Vocalization frequency and duration are coded in separate hindbrain nuclei. Nat Commun. 2: 346. PMCID: PMC3166519
  • Ulrich, F., Ma L. H., Baker, R., and Torres-Vazquez J (2011). Neurovascular development in the embryonic zebrafish hindbrain. Dev Biol. 375:134-51.

  • Ma, L. H., Gilland, E., Bass, A. H., and Baker, R. ( 2010). Ancestry of motor innervation to pectoral fin and forelimb. Nat Commun. 1: 1-8. PMCID: PMC2963806

  • Lyons, PJ, Ma, L. H., Baker, R, and Fricker, L. D. (2010). Carboxypeptidase A6 in zebrafish development and implications for VIth cranial nerve pathfinding. PLoS One 5: e12967. PMCID: PMC2945764

  • Straka H. and Baker R. ( 2011) Vestibular System Anatomy and Physiology. In: Farrell A.P., (ed.), Encyclopedia of Fish Physiology: From Genome to Environment, 1: 244–251. San Diego: Academic Press

Research Image