Cerebral cortexThe cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of allocortex. It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemispheres. The two hemispheres are joined beneath the cortex by the corpus callosum. The cerebral cortex is the largest site of neural integration in the central nervous system.
Motor cortexThe motor cortex is the region of the cerebral cortex involved in the planning, control, and execution of voluntary movements. The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately anterior to the central sulcus. The motor cortex can be divided into three areas: 1. The primary motor cortex is the main contributor to generating neural impulses that pass down to the spinal cord and control the execution of movement. However, some of the other motor areas in the brain also play a role in this function.
Basal gangliaThe basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an external and internal region, and in the division of the striatum. The basal ganglia are situated at the base of the forebrain and top of the midbrain. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas.
Cortex (anatomy)In anatomy and zoology, the cortex (: cortices) is the outermost (or superficial) layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the best-known of all cortices. The word is of Latin origin and means bark, rind, shell or husk.
Prefrontal cortexIn mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, and BA47. The basic activity of this brain region is considered to be orchestration of thoughts and actions in accordance with internal goals. Many authors have indicated an integral link between a person's will to live, personality, and the functions of the prefrontal cortex.
Thalamocortical radiationsIn neuroanatomy, thalamocortical radiations also known as thalamocortical fibres, are the efferent fibres that project from the thalamus to distinct areas of the cerebral cortex. They form fibre bundles that emerge from the lateral surface of the thalamus. Thalamocortical fibers (TC fibres) have been referred to as one of the two constituents of the isothalamus, the other being microneurons. Thalamocortical fibers have a bush or tree-like appearance as they extend into the internal capsule and project to the layers of the cortex.
Cortico-basal ganglia-thalamo-cortical loopThe cortico-basal ganglia-thalamo-cortical loop (CBGTC loop) is a system of neural circuits in the brain. The loop involves connections between the cortex, the basal ganglia, the thalamus, and back to the cortex. It is of particular relevance to hyperkinetic and hypokinetic movement disorders, such as Parkinson's disease and Huntington's disease, as well as to mental disorders of control, such as attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder (OCD), and Tourette syndrome.
Primary somatosensory cortexIn neuroanatomy, the primary somatosensory cortex is located in the postcentral gyrus of the brain's parietal lobe, and is part of the somatosensory system. It was initially defined from surface stimulation studies of Wilder Penfield, and parallel surface potential studies of Bard, Woolsey, and Marshall. Although initially defined to be roughly the same as Brodmann areas 3, 1 and 2, more recent work by Kaas has suggested that for homogeny with other sensory fields only area 3 should be referred to as "primary somatosensory cortex", as it receives the bulk of the thalamocortical projections from the sensory input fields.
Basal ganglia diseaseBasal ganglia disease is a group of physical problems that occur when the group of nuclei in the brain known as the basal ganglia fail to properly suppress unwanted movements or to properly prime upper motor neuron circuits to initiate motor function. Research indicates that increased output of the basal ganglia inhibits thalamocortical projection neurons. Proper activation or deactivation of these neurons is an integral component for proper movement.
Motor neuronA motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly control effector organs, mainly muscles and glands. There are two types of motor neuron – upper motor neurons and lower motor neurons. Axons from upper motor neurons synapse onto interneurons in the spinal cord and occasionally directly onto lower motor neurons.
Upper motor neuronUpper motor neurons (UMNs) is a term introduced by William Gowers in 1886. They are found in the cerebral cortex and brainstem and carry information down to activate interneurons and lower motor neurons, which in turn directly signal muscles to contract or relax. UMNs in the cerebral cortex are the main source of voluntary movement. They are the larger pyramidal cells in the cerebral cortex. There is a type of giant pyramidal cell called Betz cells and are found just below the surface of the cerebral cortex within layer V of the primary motor cortex.
Medullary pyramids (brainstem)In neuroanatomy, the medullary pyramids are paired white matter structures of the brainstem's medulla oblongata that contain motor fibers of the corticospinal and corticobulbar tracts – known together as the pyramidal tracts. The lower limit of the pyramids is marked when the fibers cross (decussate). The ventral portion of the medulla oblongata contains the medullary pyramids. These two ridge-like structures travel along the length of the medulla oblongata and are bordered medially by the anterior median fissure.
BrainstemThe brainstem (or brain stem) is the stalk-like part of the brain that interconnects the cerebrum and diencephalon with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch. The brainstem is very small, making up around only 2.6 percent of the brain's total weight. It has the critical roles of regulating cardiac, and respiratory function, helping to control heart rate and breathing rate.
Dorsolateral prefrontal cortexThe dorsolateral prefrontal cortex (DLPFC or DL-PFC) is an area in the prefrontal cortex of the primate brain. It is one of the most recently derived parts of the human brain. It undergoes a prolonged period of maturation which lasts into adulthood. The DLPFC is not an anatomical structure, but rather a functional one. It lies in the middle frontal gyrus of humans (i.e., lateral part of Brodmann's area (BA) 9 and 46). In macaque monkeys, it is around the principal sulcus (i.e., in Brodmann's area 46).
Pyramidal cellPyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal cells are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. Pyramidal neurons are also one of two cell types where the characteristic sign, Negri bodies, are found in post-mortem rabies infection. Pyramidal neurons were first discovered and studied by Santiago Ramón y Cajal.
Parkinson's diseaseParkinson's disease (PD), or simply Parkinson's, is a chronic degenerative disorder of the central nervous system that affects both the motor system and non-motor systems. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms become more common. Early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking. Problems may also arise with cognition, behaviour, sleep, and sensory systems. Parkinson's disease dementia becomes common in advanced stages of the disease.
Visual cortexThe visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 (V1), Brodmann area 17, or the striate cortex.
Cingulate cortexThe cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe. It receives inputs from the thalamus and the neocortex, and projects to the entorhinal cortex via the cingulum. It is an integral part of the limbic system, which is involved with emotion formation and processing, learning, and memory.
ClaustrumThe claustrum (Latin, meaning "to close" or "to shut") is a thin sheet of neurons and supporting glial cells, that connects to the cerebral cortex and subcortical regions including the amygdala, hippocampus and thalamus of the brain. It is located between the insula laterally and the putamen medially, separated by the extreme and external capsules respectively. Blood to the claustrum is supplied by the middle cerebral artery.
GanglionA ganglion (: ganglia) is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies.
