Subcortical Nuclei And Structures Flashcards
List the structures part of the limbic system
- hippocampus
- amygdala
- thalamus
- hypothalamus
- hypophysis
What is the function of the hippocampus ?
Part of the limbic system.
It is mostly involved in memory processes (declarative and long term memory). It is found on the floor of the posterior horn of the lateral ventricle. It can be divided into 4 fields from CA1-4 (cornu ammonia) in relation to the connection to other cortical areas, such as the PFC and AC.
What is the role of the amygdala ?
Part of the limbic system.
Involved in memory.
Seems to play a role in emotional and planning processes.
It is mostly involved in emotional processes related to memory, memory consolidation and decision making. This structure also plays a role in selective attention. It is the center of innate and acquired fears which explains its participation in emotional memory.
What is the role of the thalamus ?
Involved with the perception/ selection of inputs and attention.
What is the role of hypothalamus ?
Production of hormones
What is the role of hypophysis ?
The production of hormones
List the innate fears sustained by amygdala
Fear of death :
- suffocation
- incapacitation
- physical injury
- isolation
- disgust
- unknown/ abnormal
What is the function of the cingulate cortex ?
Located just above the corpus callosum it spreads postero anteriorly along the temporal, parietal and frontal lobes. It doesn’t possess a specific function but plays a role in different processes most of them involved in reasoning, higher cognitive functions and its connection to memory and emotions. It can be divided into 2 main parts : aCC and pCC.
What is the role of the thalamus ?
The thalamus is an assemble of nuclei that links the peripheral system of inputs gathering to the central system of analysis, decision and execution. The thalamus also plays a role in the perception of environnement.
List the thalamic nuclei in working pairs
Anterior nucleus (AN)- Laterodorsal nucleus (LD)
Midline nucleus (Mid)- Dorsomedial nucleus (DM)
Ventroanterior nucleus (VA)- Ventrolateral nucleus (VL)
Ventral posterolateral nucleus (VPL)- Ventral posteromedial nucleus (VPM)
Lateral posterior nucleus (LP) - Pulvinar nucleus (Pull)
Lateral geniculate body (LGB)- Medial geniculate body (MGB)
Interalaminar nucleus (IL) - Centromedian nucleus (CM)
What is the function of the hypothalamus ?
The hypothalamus is composed of 9 nuclei. It’s main function is the connection between the nervous system and the endocrine system, especially the production of hormones such as oxytocin and vasopressin (paraventricular nucleus) - to regulate the autonomous functions of the body.
What are the 9 nuclei composing the hypothalamus ?
- Posterior nucleus
- Dorsal hypothalamic nucleus
- Lateral nucleus
- Paraventricular nucleus (vasopressin)
- Preoptic nucleus
- Anterior nucleus
- Supra optic nucleus
- Ventromedial nucleus
- Dorsomedial nucleus
(Mammillary bodies)
Describe the anatomy of the hypophysis
Composed of two lobes, the anterior lobe is called Adenohypophysis and the posterior lobe is called neurohypophysis. The third ventricle of the hypothalamus is linked to the hypophysis through the infundibular stalk. There one can find Herring bodies (vesicles filled with oxytocin and vasopressin).
What is the function of the basal nuclei ?
It is an assemble of nuclei involved in the regulation of almost all systems, especially the regulation of motor processes.
List the different nuclei of the basal nuclei
- striatum :
Dorsal —> caudate nucleus + putamen
Ventral —> nucleus accumbens + olfactory tubercle - globus pallidus (Gpe + Gpi)
- substantia nigra
- Nucleus Basales Meynert
What is the function of the striatum ?
With a direct connection to the cerebral cortex, for both inputs and outputs, the striatum can be considered as a doorway that quickly connects those 2 systems.
Describe the anatomy of the striatum ?
Dorsal striatum :
- caudate nucleus
- putamen
Ventral striatum :
- accumbens nucleus
- olfactory tubercle of the end of CN1
What is the function of the putamen ?
It is involved in the regulation of movements and goal-directed/ addictive behaviors, presenting significative difference in size between male and female subjects. It connects directly to the cerebral cortex and other basal nuclei, especially Gpe and Gpi, participating in a self regulatory loop of the other structures.
What is the function and anatomy of the Substantia nigra
It is divided in 2 anatomical parts : pars compact and pars reticulate. It is the most relevant producer of dopamine for the central nervous system and the main output nucleus for regulatory pathways.
What is the function of Nucleus Basales Meynert ?
Its function is not fully understood. It is connected (Ach) to different parts of the frontal and temporal cortices and the amygdala, showing a decreased volume in different types of dementia and sever cognitive deficits which suggests an excitatory / regulatory role in rational and emotional processes.
What is the function of the Claustrum ?
It is not included into the basal nuclei. It evolves into a nucleus with the function of building a connection between cortical areas for high cognitive functions such as processing sensory information from the environnement before attribution of meaning. It is still interconnected with the ventral portion of the temporal lobe and has a high neuro plasticity thanks to a high concentration in brain derived neurotrophic factor and growth neurotrophic factor. In disorders of consciousness, it can be used as an on/off switch for deep brain stimulation.
What is the function of the Locus Coeruleus
It is a deep brainstem nuclei which main function is to produce norepinephrine, making it the origin of far-reaching noradrenergic systems in the brain, affecting behavior, memory and hormone regulation.
What is the function of Raphe nuclei ?
Composed of 6 nuclei which belong to the reticular formation and are deeply embedded in the brainstem. Their main function is the production of serotonin but not all neurons of this group are serotonergic : the occurrence varying from 10% to 8memory 80% of clusters depending on the nucleus.
List the nuclei composing the Raphe nuclei
Rostral Raphe Group :
- dorsal
- linear
- median
Caudal Raphe group :
- magnus
- obscurus
- pallidus
