Functional recovery from sciatic nerve crush lesion in the rat correlates with individual differences in responses to chronic intermittent stress

Abstract

The aim of the present study was to monitor the influence of chronic stress on functional recovery from a sciatic nerve crush lesion in the rat. Male Wistar rats underwent standard unilateral sciatic nerve crush. Subsequently, chronic stress was induced during the recovery phase using a daily 30 min shock box session where rats received three electric footshocks each session (0.5 sec, 1 mA). Reduced body weight gain, adrenal gland hypertrophy, and thymus involution indicated that the stress rats were chronically stressed. Evaluation of sensorimotor function revealed significant differences in recovery between control and stress groups. Correlational analysis of individual stress rats indicated that recovery of the walking pattern was negatively correlated with adrenal gland and medulla enlargement, thymus involution, and plasma levels of adrenocorticotrophic hormone (ACTH) and corticosterone 45 min following the final stress session. In control rats, the index of sciatic nerve function (SF index, expressed as the difference between the injured paw and the intact contralateral paw as a percentage) was significantly correlated with adrenal medulla weight only. The present study reveals that chronic intermittent footshock stress impedes sensorimotor recovery following a sciatic nerve crush lesion and that the consequences of chronic intermittent stress are individually determined. We suggest that the quality of functional locomotor recovery after nerve crush lesion is related to the adaptive capacity or coping style of the individual rat.

Sciatic nerve injury: A simple and subtle model for investigating many aspects of nervous system damage and recovery

“…Differential regeneration into the peripheral targets of the L4 and L5 DRGs has been reported (Puigdellivol-Sanchez et al, 2005), while full sensory and motor recovery after SNA has been described in as little as three weeks in rats (Vogelaar et al, 2004). Stress appears to affect several parameters of recovery (van Meeteren et al, 1997), and the process is clearly responsive to sex-specific steroids (Roglio et al, 2008) and age (Kang and Lichtman, 2013).…”

Whisking Recovery After Automated Mechanical Stimulation During Facial Nerve Regeneration

“…Chronic stress deteriorates the efficiency of these processes; for example, activation of the autonomic nervous system causes epineural vasoconstriction and reduces endoneural nerve blood flow. 24 Likewise, Amako et al found suppressed sciatic nerve recovery after water-immersion stress in rats. 25 …”

“…However, it is possible that WA treatment produced occult stress that offset potentially beneficial effects of the treatment, explaining why whisking recovery that was similar to, or worse than, that of the restrained control rats, as has been demonstrated in prior studies; Van Meeteren et al demonstrated that chronic intermittent stress impaired nerve regeneration in a sciatic nerve model. 24 The nerve regeneration process is controlled by neuroendocrine, immunologic and autonomic nervous system factors. Chronic stress deteriorates the efficiency of these processes; for example, activation of the autonomic nervous system causes epineural vasoconstriction and reduces endoneural nerve blood flow.…”

Effects of swimming exercise on nerve regeneration in a rat sciatic nerve transection model

“…However, conflicting results on peripheral nerve regeneration have been reported; some studies have reported that both the forced exercises may cause detrimental effects, especially on the restoration of muscle function [3, 4]. Stress induced by forced physical training could be a factor that may impede functional recovery after nerve injury [5]. …”