Anesthesia and brain sensory processing: impact on neuronal responses in a female songbird.

G Karino,L Loison,G De Groof,M Hausberger,C Heyraud,I George,H Cousillas

doi:10.1038/srep39143

Abstract

Whether anesthesia impacts brain sensory processing is a highly debated and important issue. There is a general agreement that anesthesia tends to diminish neuronal activity, but its potential impact on neuronal “tuning” is still an open question. Here we show, based on electrophysiological recordings in the primary auditory area of a female songbird, that anesthesia induces neuronal responses towards biologically irrelevant sounds and prevents the seasonal neuronal tuning towards functionally relevant species-specific song elements.

Highlights

Different vocal behavior, there is a strong adult vocal plasticity in Starlings but not in zebra finch
Whether anesthetics may affect the tuning properties of central neurons remains under debate, despite of the fact that this is a major issue: a better knowledge of the effects of anesthesia on neuronal properties is essential as otherwise anesthesia could lead us to potential major errors of interpretation
We were able to demonstrate that Field L neurons of awake adult female starlings are tuned to species-specific song elements that are produced by both males and females (Class II and Class III songs; Fig. 1), Figure 2

Summary

Materials and Methods

These planes were precisely located with reference to the bifurcation of the sagittal sinus: 2.5 mm rostral and 1 mm in each hemisphere These coordinates ensured that recordings were made in Field L centered on the L2 sub-area described by Capsius and Leppelsack[38] and Cousillas et al.[39]. The artificial non-specific stimuli composed by pure tones and white noise allowed us to assess the presence of the tonotopic organization that is characteristic of Field L18,39 This procedure allowed us to avoid a postmortem analysis of the recording sites, as required by the 3 R ethical considerations and to keep the birds alive for future behavioral experiments. Four-way repeated-measures ANOVAs and Tukey HSD tests (R 2.15.2, R Foundation for Statistical Computing) were performed to test for potential differences between the two conditions (awake or anesthetized), the two hemispheres, the two seasons and the different classes of stimuli, as well as the conditions (anesthetized/awake) Data were normalized using an arcsin square-root transform

Author Contributions

Findings

Additional Information