The Functional Integration in the Sensory-Motor System Predicts Aging in Healthy Older Adults

Abstract

Healthy aging is typically accompanied by a decrease in the motor capacity. Although the disrupted neural representations and performance of movement have been observed in older age in previous studies, the relationship between the functional integration of sensory-motor (SM) system and aging could be further investigated. In this study, we examine the impact of healthy aging on the resting-state functional connectivity (rsFC) of the SM system, and investigate as to how aging is affecting the rsFC in SM network. The SM network was identified and evaluated in 52 healthy older adults and 51 younger adults using two common data analytic approaches: independent component analysis and seed-based functional connectivity (seed at bilateral M1 and S1). We then evaluated whether the altered rsFC of the SM network could delineate trajectories of the age of older adults using a machine learning methodology. Compared with the younger adults, the older demonstrated reduced functional integration with increasing age in the mid-posterior insula of SM network and increased rsFC among the sensorimotor cortex. Moreover, the reduction in the rsFC of mid-posterior insula is associated with the age of older adults. Critically, the analysis based on two-aspect connectivity-based prediction frameworks revealed that the age of older adults could be reliably predicted by this reduced rsFC. These findings further indicated that healthy aging has a marked influence on the SM system that would be associated with a reorganization of SM system with aging. Our findings provide further insight into changes in sensorimotor function in the aging brain.

Can you be too old for oral implants? An update on ageing and plasticity in the oro‐facial sensorimotor system

“…In the case of the ageing‐related changes in the CNS, anatomical (eg, decreased grey matter volume), biochemical (eg, altered neurotransmitter levels) and physiological (eg, altered neural activity and excitability) changes can occur in many CNS areas. These include several subcortical regions (eg, cerebellum, basal ganglia) involved in sensorimotor behaviour and related functions (cognition, memory, etc) as well as the sensorimotor cortex and associated cortical regions such as the supplementary motor area and prefrontal cortex, and also the hippocampus . The changes include a progressive loss of neuronal dendritic spines and synapses, alterations in CNS levels of neurotransmitters and decreased volume of neuronal cell bodies, although there may be no actual loss of neurons per se in some CNS areas .…”

“…These include several subcortical regions (eg, cerebellum, basal ganglia) involved in sensorimotor behaviour and related functions (cognition, memory, etc) as well as the sensorimotor cortex and associated cortical regions such as the supplementary motor area and prefrontal cortex, and also the hippocampus. 94,96,[103][104][105][106] The changes include a progressive loss of neuronal dendritic spines and synapses, alterations in CNS levels of neurotransmitters and decreased volume of neuronal cell bodies, although there may be no actual loss of neurons per se in some CNS areas. 104,105,107,108 The changes may also include decreased connectivity between a number of CNS areas involved in sensorimotor functions may explain why ageing may be associated with decreased sensorimotor performance manifested as impaired sensorimotor integration and decreased ability to modulate complex sensorimotor activities built upon a framework of neural activities across several sensorimotor networks.…”

“…94,96,[103][104][105][106] The changes include a progressive loss of neuronal dendritic spines and synapses, alterations in CNS levels of neurotransmitters and decreased volume of neuronal cell bodies, although there may be no actual loss of neurons per se in some CNS areas. 104,105,107,108 The changes may also include decreased connectivity between a number of CNS areas involved in sensorimotor functions may explain why ageing may be associated with decreased sensorimotor performance manifested as impaired sensorimotor integration and decreased ability to modulate complex sensorimotor activities built upon a framework of neural activities across several sensorimotor networks. Furthermore, since improved sensorimotor performance in healthy older adults is accompanied by increased connectivity in CNS components of the sensorimotor system, 106 therapeutic approaches that prevent or minimise loss of sensory-motor connectivity or promote connectivity may be able to prevent or even reverse sensorimotor impairments in older adults.…”

Effects of lorazepam and baclofen on short‐ and long‐latency afferent inhibition

“…), possibly reflecting an age‐related decline in sensorimotor function (He et al . ). Therefore, measures of afferent inhibition can be used to assess the integrity of the sensorimotor system and probe sensorimotor function.…”

“…Abnormal LAI is seen in individuals with sensorimotor deficits, including Parkinson's disease (Sailer et al 2003) and complex regional pain syndrome (Morgante et al 2017). Furthermore, the magnitude of SAI and LAI declines with age (Young-Bernier et al 2012Bhandari et al 2016), possibly reflecting an age-related decline in sensorimotor function (He et al 2017). Therefore, measures of afferent inhibition can be used to assess the integrity of the sensorimotor system and probe sensorimotor function.…”