Non-invasive stimulation of the vibrissal pad improves recovery of whisking function after simultaneous lesion of the facial and infraorbital nerves in rats

Abstract

We have recently shown that manual stimulation of target muscles promotes functional recovery after transection and surgical repair to pure motor nerves (facial: whisking and blink reflex; hypoglossal: tongue position). However, following facial nerve repair, manual stimulation is detrimental if sensory afferent input is eliminated by, e.g., infraorbital nerve extirpation. To further understand the interplay between sensory input and motor recovery, we performed simultaneous cut-and-suture lesions on both the facial and the infraorbital nerves and examined whether stimulation of the sensory afferents from the vibrissae by a forced use would improve motor recovery. The efficacy of 3 treatment paradigms was assessed: removal of the contralateral vibrissae to ensure a maximal use of the ipsilateral ones (vibrissal stimulation; Group 2), manual stimulation of the ipsilateral vibrissal muscles (Group 3), and vibrissal stimulation followed by manual stimulation (Group 4). Data were compared to controls which underwent surgery but did not receive any treatment (Group 1). Four months after surgery, all three treatments significantly improved the amplitude of vibrissal whisking to 30° versus 11° in the controls of Group 1. The three treatments also reduced the degree of polyneuronal innervation of target muscle fibers to 37% versus 58% in Group 1. These findings indicate that forced vibrissal use and manual stimulation, either alone or sequentially, reduce target muscle polyinnervation and improve recovery of whisking function when both the sensory and the motor components of the trigemino-facial system regenerate.

Neuropathology in sensory, but not motor, brainstem nuclei of the rat whisker circuit after diffuse brain injury

“…DOI: 10.3109/08990220.2014.897602 by mechanical forces on the cortex in contrast to surgical transection, compression, or extirpation of the facial nerve. In each case, the peripheral injury was followed by a reduction of total neuron numbers and partial to complete loss of nerve-associated motor function (Waite 1984;Johnson and Duberley 1998;Pavlov et al 2008;Marzo et al 2010;Bendella et al 2011;Dauer et al 2011). Thus, the results of these previous studies are likely not directly comparable.…”

Selective Denervation of the Facial Dermato-Muscular Complex in the Rat: Experimental Model and Anatomical Basis

“…Specifically, it may aid to investigate the interplay between the afferent and efferent nerval innervation of the face, which is not entirely understood yet. The facial anatomy of rats presents very advantageous model for the investigation of the trigemino-facial system, as the whisker pad muscles are innervated afferent as well as efferent (Bendella et al, 2011). For subsequent analyses of the models, we demonstrated a whole-mount immunofluorescent staining protocol for these facial muscles to investigate their neuromuscular innervation and regeneration.…”

“…Therefore, the trigeminal and facial nerves in the rat are highly relevant structures in neurological research. Various experimental models for researching the facial nerve (Kreutzberg et al, 1989;Moran andGraeber, 2004, Guntinas-Lichius et al, 2011;Olmstead et al, 2015) the trigeminal nerve (Titmus and Faber, 1990;Pavlov et al, 2008;Bendella et al, 2011;Bregman et al, 2014;Ding et al, 2017;Dingle et al, 2019) have been established. Despite this widespread research surrounding cranial nerves, currently, there is no comprehensive surgical model for total deafferentation or deefferentation of superficial facial structures established in the rat.…”

Hypoglossal-Facial Nerve Reconstruction Using a Y-Tube-Conduit Reduces Aberrant Synkinetic Movements of the Orbicularis Oculi and Vibrissal Muscles in Rats

“…These periodic “microvibrissal placements” are synchronized with macrovibrissal movements not only during free exploration, but also during texture discrimination tasks [ 37 , 38 ]. As a result, during our 3–5-minute video sessions, natural head movements result in some variability in whisking effort [ 39 ].…”