Spinal-cord brainstem bulb {medulla, brain}| {medulla oblongata} includes basal ganglia and continues major nerve tracts. It relays auditory nerve sense and motor nerves, mediating phonation and articulation. It regulates cardiac action, chewing, tasting, swallowing, coughing, sneezing, salivation, vomiting, and sucking in newborns. Respiratory center maintains respiration. Some medulla-oblongata neurons make epinephrine.
A limbic-system part {amygdala}| includes insula white matter.
location
Insula is in posterior frontal lobe and anterior temporal lobe.
input
Lateral amygdala receives sensations slowly from sensory cortex and fast from thalamus, and receives memories from medial temporal lobe. Central amygdala receives from lateral amygdala, prefrontal cortex, and basal amygdala. Basal amygdala receives from lateral amygdala, medial temporal lobe, and prefrontal cortex.
output
Amygdala dopamine neurons connect to cholinergic neurons in medial septal nucleus, nucleus accumbens, nucleus basalis magnocellularis, nucleus of diagonal band of Broca, hypothalamus regions for motivation and reward, and sense and motor cerebral cortex upper layers.
Amygdala sends to orbitofrontal prefrontal cortex, mediodorsal thalamic nucleus, and hippocampal formation.
Lateral amygdala sends to central amygdala. Central amygdala sends to lateral hypothalamus for blood pressure, paraventricular hypothalamus for hormones, motor cortex for stopping, and basal amygdala. Basal amygdala sends to central amygdala.
functions
Amygdala compares new stimulus to previous stimuli and signals differences to other brain regions. Using memory, amygdala participates in habituation and anticipation.
Amygdala {basolateral nucleus} affects aggression, dominance, submission, and territoriality behaviors. Amygdala regulates fear and emotional behavior. Amygdala regulates visceral activity. Amygdala affects vision and smell.
damage
Removal of, or injury to, amygdala does not affect memory.
drug
Cocaine affects sublenticular extended amygdala.
Medulla ganglia {basal ganglia}| include amygdala, caudate nucleus, claustrum, external-capsule fibers, globus pallidus, internal-capsule fibers, lentiform nucleus, nucleus basalis of Meynert, nucleus dorsalis, putamen, septal nuclei, substantia nigra pars reticulata, and subthalamic nucleus.
input
Basal ganglia receive from basal-midbrain-nuclei dopaminergic neurons.
output
Basal-ganglia cholinergic neurons send to motor cortex for transmission to muscles [Langston and Palfreman, 1995].
functions
Basal ganglia assemble, select, and trigger automatic movements, perceptual motor coordination, ballistic movements, and proprioceptively controlled movements, using movement plans. They track moving visual objects, control eye movements, and process visual and multisensory data. They control tremor and muscle tone. Basal ganglia coordinate with neocortex and cerebellum for posture and complex voluntary movements.
Medulla basal ganglia {caudate nucleus} can inhibit globus pallidus. Caudate nucleus receives excitatory input from cerebral cortex and inhibitory input from thalamus, substantia nigra, and raphe. Caudate nucleus is for memory and obsessive behavior.
Medulla basal ganglia {claustrum} can lie under cerebral cortex near insula and project to many cortex regions.
Putamen and globus pallidus {lenticular nuclei} look striated because they have myelinated tracts.
Brainstem regions {motor reticular formation} can facilitate spinal mediated reflexes and transmit feedback from higher centers to primary receptors.
Basal ganglia nuclei {nucleus basalis of Meynert} {nuclei of Meynert} {Meynert nuclei} {substantia innominata} can have cholinergic neurons and send to cerebral cortex.
Basal ganglia nucleus {nucleus dorsalis} receives proprioception input from spinal cord.
Brainstem regions {globus pallidus} {pallidum} can receive from red nucleus and inhibit thalamus and subthalamic nucleus. Dopamine neurons can cause rigidity if overstimulated. Choline neurons can cause hyperkinesis, chorea, and athetosis if overstimulated.
Basal ganglia connect to thalamus, then to cortex, then back to basal ganglia {polysynaptic loop}.
Medulla basal ganglia {putamen} can receive excitatory input from cerebral cortex and inhibitory input from thalamus, substantia nigra, and raphé nucleus. It inhibits globus pallidus. Putamen is for memory, motor skill, and obsessiveness. It has nearby-space maps, used in motor control.
Brainstem regions {raphé dorsalis} can send motor input to superior colliculi.
Medulla nuclei {raphé nuclei} can secrete serotonin, make peptide substance P, start light sleep, and modulate pain, using spinal-cord dorsal-horn presynaptic inhibition.
Forebrain basal ganglia {septal nuclei} {septum, medulla} can receive from hippocampus and reticular formation and send to hippocampus, hypothalamus, and midbrain. Septal nuclei have trophotropic centers. They can control aggressiveness. They organize sexual thoughts, emotions, and action. They are in or near region that causes pleasure when excited.
Putamen, globus pallidus, and caudate nucleus {corpus striatum} {striatum} are near thalamus. They look striated because they have myelinated tracts.
no layers
Corpus striatum neuron types mix but not in layers.
maps
Most maps in mammalian cortex connect to maps in corpus striatum.
functions
Corpus striatum integrates learned automatic movement sequences, such as voluntary eye movements.
input
Some striatum neurons receive from thousands of cortical neurons that send 10-Hz to 40-Hz oscillating signals {interval timer}. Stimuli synchronize oscillations. Oscillators then go on oscillating. Second stimuli make substantia nigra send dopamine to striatum. Striatum remembers signal pattern. If starting signal repeats, dopamine repeats.
output
If pattern matches, striatum signals to thalamus, which informs cortex.
Medulla regions {respiratory center} can send excitatory signals along phrenic nerve to diaphragm.
Nuclei {subthalamic nucleus} {Luys nucleus} {Luys body} {nucleus of Luys} {body of Luys} can be near hypothalamus, inhibit globus pallidus, and send to thalamus. Damage causes ballistic movement.
4-Zoology-Organ-Nerve-Brain-Brainstem-Hindbrain
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Date Modified: 2022.0225