Spatiotemporal sequences of neuronal activity encode odor information
in the olfactory bulb
A.U. Nicol1, A Segonds-Pichon1, K.M. Kendrick1 and M.S. Magnusson2
1Babraham Institute, Cambridge,
UK,
2Human Behaviour Laboratory, University of Iceland, Reykjavik, Iceland
Spontaneously recurring complex sequences of neuronal activity were recently
demonstrated in action potential (spike) generation amongst simultaneously
sampled multiple neurons and in postsynaptic potentials. Using Theme
(PatternVision Ltd, Iceland) developed for detecting non-randomly recurring
real-time sequential patterns (T-patterns) in behavior and interactions,
we have inquired whether such patterns exist in the olfactory bulb (OB)
and if so whether they have functional significance. In accordance with
the Animals (Scientific Procedures) Act 1986 (UK), an electrode array
(5x6 or 6x8 electrodes, 350µ or 250µ separation respectively,
sampling area 2.2mm2) was positioned in the OB (mitral layer) in 8 anaesthetised
rats. Spikes were sampled in equivalent periods preceding and during 10s
odour presentations (amyl acetate, cineole) at various concentrations.
Breathing was recorded as markers of peak inhale and peak exhale. Long
t-patterns were identified. Often these patterns spanned the entire array.
A considerable proportion incorporated breathing, and these patterns are
the focus here. The incidence and length of breathing-related sequences
varied with ventilatory phase and odour quality. Thus, in the OB, precise
sequences of neuronal discharge encode olfactory information.
Paper presented
at Measuring Behavior 2005
, 5th International Conference on Methods and Techniques
in Behavioral Research, 30 August - 2 September 2005, Wageningen, The
Netherlands.
© 2005 Noldus
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