INIBIBB   05455
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BAHIA BLANCA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Synaptic engineering: an ionic switch of behavior
Autor/es:
RAYES, D.H.; PIRRI, J.; ALKEMA, M.
Reunión:
Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2013
Resumen:
The unraveling of the human brain connectivity
map is considered as an essential step in the understanding how the brain
controls behavior. However, the connectivity map does not carry information
about the sign of synaptic connections. Is it possible to reverse the
behavioral output of a circuit by changing the sign of a synapse? Does the sign
of a synapse provide constraints to the development and the specification of a
connectome? We address these questions using the neuronal circuit of the C.
elegans escape response in which tyraminergic neurons coordinate the
suppression of head movements with backward locomotion through the activation
of tyramine-gated Cl- channel LGC-55. Amino acid substitution allowed us to
change the selectivity of LGC-55 from Cl- to Na +. Localization of LGC-55
cation channel is indistinguishable from wild-type LGC-55. Exogenous tyramine
induces neck muscle relaxation and backward locomotion in the wild-type
animals, but induces neck muscle contraction and forward locomotion in
transgenic animals that express the LGC-55 cation. Similarly, touch or
optogentically induced release of endogenous tyramine triggers opposite
behavioral responses in animals that express the LGC-55 cation vs LGC-55 anion
channel. Our data show that changing the nature of a synapse within a neural
circuit can reverse its behavioral output and indicate that the C. elegans
connectome is established independent of the nature of synaptic activity or
behavioral output.