Selection of head and whisker coordination strategies during goal-oriented active touch

Abstract

In the rodent whisker system, a key model for neural processing and behavioral choices during active sensing, whisker motion is increasingly recognized as only part of a broader motor repertoire employed by rodents during active touch. In particular, recent studies suggest whisker and head motions are tightly coordinated. However, conditions governing the selection and temporal organization of such coordinated sensing strategies remain poorly understood. We videographically reconstructed head and whisker motions of freely moving mice searching for a randomly located rewarded aperture, focusing on trials in which animals appeared to rapidly "correct" their trajectory under tactile guidance. Mice orienting after unilateral contact repositioned their whiskers similarly to previously reported head-turning asymmetry. However, whisker repositioning preceded head turn onsets and was not bilaterally symmetric. Moreover, mice selectively employed a strategy we term contact maintenance, with whisking modulated to counteract head motion and facilitate repeated contacts on subsequent whisks. Significantly, contact maintenance was not observed following initial contact with an aperture boundary, when the mouse needed to make a large corrective head motion to the front of the aperture, but only following contact by the same whisker field with the opposite aperture boundary, when the mouse needed to precisely align its head with the reward spout. Together these results suggest that mice can select from a diverse range of sensing strategies incorporating both knowledge of the task and whisk-by-whisk sensory information and, moreover, suggest the existence of high level control (not solely reflexive) of sensing motions coordinated between multiple body parts.

OptoZIF Drive: a 3D printed implant and assembly tool package for neural recording and optical stimulation in freely moving mice

“…EMG wires run anterior to the eyes, where they meet the scalp resection and are adhered to the skull with dental cement (figure 1(a)). Mice had been trained to locate a randomly positioned reward-port in the dark using whisker palpations [28]. We sought to deliver optical stimulation to primary somatosensory cortex (SI) that was timed to the whisker motions of the animal using the EMG signal.…”

“…anesthetized preps, head fixation, and whisker trimming in the rodent whisker system). The importance of experiments that allow for more natural behaviors is also becoming clear [28]. By incorporating the ability to easily perform closed-loop stimulation experiments within a drive that has been engineered to accommodate more natural behaviors (i.e.…”

Whisking asymmetry signals motor preparation and the behavioral state of mice

“…Earlier work has shown that whisker asymmetry arises and is related to movement of the head (Towal and Hartmann, 2006;Grant et al, 2009;Schroeder and Ritt 2016). These earlier studies were all in freely moving animals.…”

“…While it is often called a model sensory system (Van der loos and Woolsey, 1973), where each whisker is associated with 1000s of neurons in the trigeminal somatosensory pathways, this system is in fact also a model motor system -with single muscles associated with each whisker (Dorfl, 1983;Sachdev et al, 2002;Grinevich et al, 2005;Haidarliu et al 2013). Not only do mice have the potential to control the motion of these tactile sensors individually, but the motion of the whiskers is often coordinated with motion of the head (Towal and Hartmann 2006;Schroeder and Ritt, 2016). Additionally, whisking can be triggered by sniffing, chewing, licking and walking (Welker 1964;Deschenes et al, 2012;Sofroniew et al, 2014).…”

Whisker touch guides canopy exploration in a nocturnal, arboreal rodent, the Hazel dormouse (Muscardinus avellanarius)

“…Mice and rats are competent climbers and possess good grasping skills (Schmidt and Fischer 2010) that are thought to be guided by a combination of olfactory, visual and tactile cues (Bhattacharyya and Bhalla 2015;Niederschuh et al 2015;Schroeder and Ritt 2016). However, the tactile whisker sense plays a primary role in environmental exploration and locomotion in both rats and mice (Vincent 1912;Watson 1907).…”