Neuroanatomy of basic cognitive function
Mark J. Ashley, David A. Hovda in Traumatic Brain Injury, 2017
Information must be moved from one cerebral area to another. Transport between subcortical and cortical areas is accomplished by projectional fibers, which comprise the internal capsule. Fibers of the internal capsule carry information both toward and away from the cortex. Axons of the internal capsule spreading out to all areas of the cortex are known as the corona radiata. Fibers from the thalamus projecting to the cortex travel in the internal capsule. Projections from the anterior and medial thalamic nuclei carry visceral and other information and project to the frontal lobe via the anterior limb of the internal capsule. Projections from the ventral anterior and ventral lateral nuclei of the thalamus travel in the genu and posterior limb of the internal capsule and reach the motor and premotor areas of the frontal lobes. The ventral posterior and medial thalamic nuclei project to the sensory cortex of the parietal lobe via the fibers of the posterior limb of the internal capsule. The posterior limb of the internal capsule also contains optic and auditory fibers. Corticobulbar (head and face muscles) and corticospinal (neck and trunk muscles) motor pathways travel via the posterior limb of the internal capsule to the brain stem (corticobulbar) and spinal cord (corticospinal).
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
The reticular nucleus of the thalamus (TRn) presents as a band of tissue at the outermost edge of the THALAMUS. In the rodent brain it sites on the inner surface of the INTERNAL CAPSULE at the lateral aspect of the thalamus. It is more or less continuous with the ZONA INCERTA, which travels from the end of the reticular nucleus towards the MIDLINE, immediately above the HYPOTHALAMUS. The thalamic reticular nucleus is divisible into functionally distinct territories (visual, auditory and somatosensory for example). It is intimately connected to other thalamic nuclei, to the CEREBRAL CORTEX and has input from neurons in the ASCENDING RETICULAR ACTIVATING SYSTEM, these various inputs and outputs existing in a highly structured, complex interaction (see Guillery et al., 1998). Functionally, the thalamic reticular nucleus is thought to be critically involved in ATTENTION, and in the modulation of SLOW-WAVE SLEEP.
Neurological Examination
Walter J. Hendelman, Peter Humphreys, Christopher R. Skinner in The Integrated Nervous System, 2017
Pathway (Figure 2.7): The corticospinal pathway descends through the white matter of the cerebral hemispheres. As the fibers funnel together between the thalamus and basal ganglia, the pathway becomes part of the internal capsule. It continues through the midbrain cerebral peduncle and the middle of the pontine bulge into the pyramid of the medulla; in the lower medulla, most of the fibers cross and continue down the spinal cord as the lateral corticospinal tract (see also Figure 1.5a). This tract is responsible for ‘instructing’ the lower motor neurons of the spinal cord regarding voluntary motor movements. For control of fine movements of the fingers, the pathway is thought to terminate directly onto the lower motor neurons. Such ‘instructions’ require both the activation of agonist muscles required for the movement and the inhibition of antagonist muscles.
Diffusion tensor imaging findings in children with sluggish cognitive tempo comorbid Attention Deficit Hyperactivity Disorder
Published in Nordic Journal of Psychiatry, 2020
Gül Ünsel-Bolat, Muharrem Burak Baytunca, Burcu Kardaş, Melis İpçi, Sevim Berrin İnci İzmir, Onur Özyurt, Mehmet Cem Çallı, Eyüp Sabri Ercan
It was reported that commission errors and continuous performance test scores in children with ADHD were associated with white matter structure of the motor pathway (some parts of the corticospinal tract). White matter microstructure of the corticospinal tract may be essential for commission errors [39,40]. The fibers of the internal capsule, which exhibited a bilateral FA increase in our study, originate in the primary motor cortex and terminate in the ventral horn of the spinal cord compose a significant part of the corticospinal tract. And, the cerebral peduncles are on the way of the projections of the internal capsule [41]. So, the internal capsule and cerebral peduncle are the subcortical white matter part of the corticospinal tract. In contrast to SCT symptoms, hyperactivity and impulsivity symptoms were reported to be associated with decreased FA values in the corticospinal tract [42]. Also, the internal capsule was implied in the patients with ADHD that have a comorbid developmental coordination disorder influencing activities of daily living and academic performance [43]. We suggest that hypoactivity as a component of SCT may be associated with alterations in the internal capsule that is a part of motor coordination. Also, the severity of apathy that is another symptom of SCT was associated with the internal capsule in Alzheimer disorder [44].
Apathetic symptoms and white matter integrity after traumatic brain injury
Published in Brain Injury, 2021
B Navarro-Main, AM Castaño-León, A Hilario, A Lagares, G Rubio, JA Periañez, M Rios-Lago
Finally, results in posterior limb of internal capsule have shown that a reduced level of FA was related with higher scores in apathy (Other-AES-I). The posterior limb of the internal capsule contains corticospinal, sensory and corticobulbar fibres, so it has been related to focal motor and sensory deficits from lesion studies, but also to apathy since classical approaches (51). Internal capsule is also included in the motor system of apathy which is expected to act on the environment in order to yield results with positive subjective value and to avoid aversive events (15). The study apathy in stroke has led to conclude that lesions to the posterior limbs of internal capsule disrupts the generation of goal-oriented behaviour (52–54). Also, Starkstein et al. (1993, 55) found a significant association between lesions in the internal capsule and a loss of motivation and goal-oriented behaviour, ranging from motor neglect to psychic akinesia and akinetic mutism. This results are in agreement with findings in patients with Alzheimer disease that show alterations in this cortico-subcortical connection structure in relation to apathy, more specifically impairing the cognitive dimension of this syndrome (56).
Longitudinal Changes in the Sensorimotor Pathways of Very Preterm Infants During the First Year of Life With and Without Intervention: A Pilot Study
Published in Developmental Neurorehabilitation, 2021
Sonia Khurana, Megan E Evans, Claire E Kelly, Deanne K Thompson, Jennifer C. Burnsed, Amy D. Harper, Karen D. Hendricks-Muñoz, Mary S Shall, Richard D Stevenson, Ketaki Inamdar, Gregory Vorona, Stacey C Dusing
DTI metrics (FA and MD) and volume were calculated for five white matter regions of interest (ROIs): i) corticospinal tract (CST), ii) posterior limb of internal capsule (PLIC), iii) corona radiata (CR), iv) cerebral peduncles (CP), and v) cerebellar peduncles (CBP). In case of cerebellar peduncle we averaged superior, middle, and inferior cerebellar peduncle together to obtain one single value each for FA and MD. However, volume was derived by adding the values of all three regions together into one. The CST was chosen to be the primary region of interest based on its importance in the output of voluntary movement, as well as the extensive literature on CST dysfunction in preterm infants.25 Likewise, the PLIC is commonly used to predict the development of cerebral palsy based on the amount of myelination.26 Lastly, the corona radiata, cerebral peduncles, and cerebellar peduncles (superior, middle, and inferior) were included based on their role in motor learning and motor processing.27,28
Related Knowledge Centers
- Caudate Nucleus
- Cerebral Hemisphere
- Putamen
- Basal Ganglia
- Brain
- Thalamus
- White Matter
- Globus Pallidus
- Afferent Nerve Fiber
- Efferent Nerve Fiber