Nervous system
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
The cerebellum (Latin for ‘little brain’) is situated directly behind the brainstem and immediately below the occipital lobe of the cerebrum (Figure 12.7). It is secured to the brainstem by three pairs of cerebellar peduncles (inferior/middle/superior = medulla/ pons/midbrain) and is often compared to a head of cauliflower in appearance. The main role of the cerebellum is to monitor and regulate coordinated movement in order to maintain balance and equilibrium. It receives information from proprioceptors situated in muscles and joints (see Chapter 4) and compares it to other signals received from the cerebrum. This allows the cerebellum to calculate and fine-tune the most efficient way to ensure muscle contraction achieves the desired result, whilst maintaining posture and balance. This information is quickly relayed (via the superior cerebellar peduncles) to the motor cortex of the cerebrum in order to coordinate muscular activity and movement. One of the reasons we stagger, and generally behave in an uncoordinated fashion, when drunk is because alcohol inhibits and impairs cerebellar proprioceptive sense. The cerebellum is also important for the timing of rhythmic movement during dancing which, in my experience at least, can also be significantly impaired by alcohol. Injury to the cerebellum does not cause paralysis but results in loss of muscle tone, uncoordinated movement (ataxia) and, on occasion, impaired thoughts about movement.
Cardiovascular physiology
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2015
The cerebellum is responsible for the control of posture and coordination of movement and is also involved in the regulation of cardiovascular responses to the integrated muscle and joint activities of exercise. Input to the cerebellum is from the cerebral cortex, the brainstem via the extra-pyramidal tracts and the vestibular system, and the ascending spinal pathways via the dorsal and ventral spinocerebellar tracts. The spinocerebellar pathways form the major afferent pathway to the cerebellum and transmit proprioceptive information from the joints, muscles and skin. Neural impulses from the cerebellar nuclei are transmitted directly to the brainstem nuclei and then to the cerebral cortex via the thalamus, or to the spinal cord. In particular, the fastigial nucleus and the uvula in the cerebellum have important cardiovascular effects. Electrical stimulation of the fastigial nucleus increases sympathetic nerve activity and arterial blood pressure, and destruction of the nucleus impairs the pressor response of animals to exercise. Electrical stimulation of different areas of the uvula can produce cardiovascular pressor or depressor effects, possibly by excitation or inhibition of RVLM sympathetic premotor cells. The uvula has afferent inputs from brainstem nuclei for balance, sight, hearing, somatosensation and pain, and it may mediate the cardiovascular responses to alerting stimuli, as are present at the onset of exercise.
The Relation of Alcohol-Induced Brain Changes to Cognitive Function
Jenny Svanberg, Adrienne Withall, Brian Draper, Stephen Bowden in Alcohol and the Adult Brain, 2014
The cerebellum is a brain structure that is located at the back of the brain, underlying the occipital and temporal lobes of the cerebral cortex. The cerebellum coordinates voluntary motor function, balance and eye movements. It is also essential to the brain networks underlying executive functions (Schmahmann, 2010; Sullivan, 2003). Atrophy of the cerebellum is commonly associated with alcoholism (see Zahr et al., 2010, for review): post-mortem studies revealed cerebellar atrophy in about 27 per cent of people with alcoholism (Lindboe and L⊘berg, 1988; Torvik, Lindboe and Rogde, 1982). Cerebellar atrophy has been confirmed by CT scan (Diener et al., 1986; Melgaard and Ahlgren, 1986) and MRI studies (Shear et al., 1996; Sullivan, 2003), showing volume deficits in both gray and white matter (Pentney et al., 2002; Sullivan, Rosenbloom and Pfefferbaum, 2000) of the vermis in patients with chronic alcohol dependence.
Effects of pyrethroids on the cerebellum and related mechanisms: a narrative review
Published in Critical Reviews in Toxicology, 2023
Fei Hao, Ye Bu, Shasha Huang, Wanqi Li, Huiwen Feng, Yuan Wang
As a functional area extremely sensitive to PYRs, the cerebellum plays an important role in the storage of motor learning memory (Kassab 2018; El-Beltagy et al. 2019). The main function of the cerebellum is to coordinate autonomous movements and maintain motor learning, posture, balance and muscle tone. Exposure to PYRs may result in a range of physiological and behavioral abnormalities, particularly motor deficits because the cerebellum is essential for gait and motor coordination. Some data indicated that PYRs had an impact on both the structural and functional development of the cerebellum (Asari et al. 2010; Kumar et al. 2013; Syed et al. 2016; Elsawy et al. 2017; Kassab 2018). Developmental exposure to PYRs impaired neonatal pivoting activity, surface rightward reflexes, and negative geotaxis reflexes. The cerebellum is believed to be involved in the execution of these behaviors and the impairment indicates developmental cerebellar damage (Syed et al. 2016). An association has also been reported between exposure to PYRs and abnormal child neurodevelopment (Ostrea et al. 2012; Shelton et al. 2014). Motor activity was also decreased in rats exposed to PYRs during development, which was associated with altered cerebellar development (Patro et al. 2009).
Transcranial Direct Current Stimulation of Motor Cortex Enhances Spike Performances of Professional Female Volleyball Players
Published in Journal of Motor Behavior, 2023
Seung-Bo Park, Doug Hyun Han, Junggi Hong, Jea-Woog Lee
In another aspect, although electrical stimulation was applied to the specific cortical area of M1 induced by tDCS in the present study, it might have affected adjacent areas, resulting in a somewhat more widespread area of target stimulation. This means that the premotor cortex, complex system of interconnected frontal lobe areas anterior to the primary motor cortex, s mainly responsible for motor functions. The upper motor neurons in the premotor cortex regulates motor behavior via extensive reciprocal connections with the primary motor cortex and axons projecting through the corticobulbar and corticospinal pathways that affect local circuit and lower motor neurons of the spinal cord and brainstem (Purves et al., 2001). In particular, the left dorsal premotor cortex activity is associated with complex motor coordination performance, meaning that tDCS has potential to improve visuomotor coordination (Pavlova et al., 2014). According to Tzvi et al. (2022), the cerebellum plays an essential role in the process of visuomotor adaptation. They noted that interaction with cortical structures, especially the premotor cortex, contributed mainly to this process. The cerebellum plays a central role in coordinating voluntary movements and motor skills including balance, coordination, and posture (Manto et al., 2012). These relationships suggest that activation of the premotor cortex and its interactions with the cerebellum could enhance the process of motor coordination by tDCS (Kwon et al., 2015; Tzvi et al., 2022).
The cannabinoid antagonist, AM251 attenuates Ataxia related deficiencies in a cerebellar ataxic model
Published in International Journal of Neuroscience, 2022
Hoda Ranjbar, Monavareh Soti, Kristi A. Kohlmeier, Vahid Sheibani, Meysam Ahmadi-Zeidabadi, Kiana Rafiepour, Mohammad Shabani
In the present study, we used a rodent model of ataxia and showed that pre-treatment with a CB1R antagonist prior to induction of cerebellar ataxia reversed the locomotor activity impairment and abnormality of gait. In our study, we utilized 3AP to damage the electron transmission chain in the inferior olive. The cerebellum is responsible for the stability of posture, maintenance of balance and coordination of motor movement [18]. Cerebellar dysfunction occurs when there is an impairment of the output of the cerebellar cortex which derives from the PCs. Impairment of the output occurs either because the PCs receive an altered input, or because the PCs themselves are damaged, or can arise as a combination of both scenarios. Altered input can result from dysfunctions in the climbing fibers which are the axons of inferior olive neurons that innervate PCs in the cerebellum, providing excitatory input. Dysfunctions in climbing fibers have been noted in ataxia in several studies [19-21]. Climbing fibers exert an enormous amount of control over the individual PCs they innervate.
Related Knowledge Centers
- Attention
- Cognition
- Emotion
- Hindbrain
- Motor Coordination
- Cerebrum
- Spinal Cord
- Brain
- Motor Control
- Sensory Nervous System