A new paper on vibrational communication and the involved neuronal
circuitry is just out in PLoS ONE. The article is, of course, open access.
Zorović M. (2011): Temporal Processing of Vibratory Communication
Signals at the Level of Ascending Interneurons in Nezara viridula
(Hemiptera: Pentatomidae). PLoS ONE 6(10): e26843.
doi:10.1371/journal.pone.0026843
Abstract: During mating, males and females of N. viridula (Heteroptera:
Pentatomidae) produce sex- and species-specific calling and courtship
substrate-borne vibratory signals, grouped into songs. Recognition and
localization of these signals are fundamental for successful mating. The
recognition is mainly based on the temporal pattern, i.e. the amplitude
modulation, while the frequency spectrum of the signals usually only
plays a minor role. We examined the temporal selectivity for vibratory
signals in four types of ascending vibratory interneurons in N.
viridula. Using intracellular recording and labelling technique, we
analyzed the neurons' responses to 30 pulse duration/interval duration
(PD/ID) combinations. Two response arrays were created for each neuron
type, showing the intensity of the responses either as time-averaged
spike counts or as peak instantaneous spike rates. The mean spike rate
response arrays showed preference of the neurons for short PDs (below
600 ms) and no selectivity towards interval duration; while the peak
spike rate response arrays exhibited either short PD/long ID selectivity
or no selectivity at all. The long PD/short ID combinations elicited the
weakest responses in all neurons tested. No response arrays showed the
receiver preference for either constant period or duty cycle. The
vibratory song pattern selectivity matched the PD of N. viridula male
vibratory signals, thus pointing to temporal filtering for the
conspecific vibratory signals already at level of the ascending
interneurons. In some neurons the responses elicited by the vibratory
stimuli were followed by distinct, regular oscillations of the membrane
potential. The distance between the oscillation peaks matched the
temporal structure of the male calling song, indicating a possible
resonance based mechanism for signal recognition.
--
Jernej Polajnar
Oddelek za entomologijo / Department of entomology
Nacionalni inštitut za biologijo / National institute of biology
Večna pot 111
SI-1000 Ljubljana
Slovenija
Tel.: +386 (0)59 232 788
Fax: +386 (0)1 2412 980
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