CNS-FA17-Limbic System Flashcards
The portion of nervous system that is responsible for mood, emotion, affective behavior (bonding) and memory?
Limbic system
T/F: Autism is believed to be a deficit in the limbic system
True
Structures associated with limbic system?
Parahippocampal gyri
Cingulatate gyri
EntoRhinal cortex
Hippocampal formation
The parahippocampus gyrus and cingulate together make up which lobe?
Limbic lobe
Cells a part of hippocampal formation?
Hippocampus proper
Subiculum
Dentate gyri
Fimbria
Portion of the hippocampal formation that contains pyramidal cells and is divided into CA1,2&3-Cornu of Ammon
Hippocampal proper
Transition zone between the parahippocampal gyrus and hippocampus is called
Subiculum
Nucleus/nucleus in the hippocampal formation that have neurons cells granule cells
Dentate gyrus
Fibers from hippocampal formation that will become the fornix?
Fimbria
Intrinsic connections:
Perforant pathway
Entorhinal cortex —> dentate gyrus —> through Mossy fibers (granule cell axon) —> CA3 —> from Pyramidal cells of CA3 —> form fimbria of formix
Collaterals fibers coming from the the alveus going to CA1
Schaffer collateral
Efferent connections of limbic system
- Entorhinal cortex to association cortex
2. Fornix to mamilary bodies
Afferent connections of the limbic system
Septal nucleus —> hippocampus
Locus ceruleus (in pons) —> hippocampus
Raphe nucleus (in reticular formation) —> hippocampus
Ventral regimental area (in midbrain) —> hippocampus
Neurotransmitter fo septal nucleus
Cholinergic -ACH
Neurotransmitter of locus ceruleus
Noradrenergic
Neurotransmitter of Raphe nucleus
5-HT (depression)- Serotonin
Ventral tegmental area neurotransmitter transmitter
Dopaminergic (schizophrenia)
Afferent connection that goes to spinal cord to relieve pain and also cortex
Reticular formation
Two types of of memory
Declarative
Procedural
Declarative memory characterized by
Renal of facts and experiences
Procedural memory characterized by
Skill i.e. writing/ walking
Memory is believed to work through long term potentiation which can be described as
High resting potential in the neurons involved
Long term potentiation allows what to occur
Perservation of memory
Reinforce memory
Plasticity
Term defined by neurons always making new connects, breaking old ones
Plasticity
Definition: loss of short term memory after the event of lesion in hippocampal formation
Anterograde amnesia
Memory can also be lost by blocking which neurotransmitter
Ach (from septal cells)
Memory is improved by increasing which neurotransmitter.
Usually done by blocking enzymes that break it down
Ach
Who proposed a circuit to explain emotions in 1938
Papez
Papez circuit
Cingulate gyrus —> hippocampal formation —> mammillary body —> anterior thalamic nuclei —> cingulate gyrus
The filing system of memory
Basal forebrain
Function of the basal forebrain
Consolidates memory
“Wake” state- keeps neurons active and responsive
Prolongs responsiveness of cortical neurons
Pleasure center
Septal area
Afferent to septal area
Comes from:
- Amygdala
- Olfactory tract
- Hippocampus
- Brainstem
Septal area efferent goes to
Hypothalamus
Brainstem
Hippocampus
Septal area function
Reward area
Memory via Ach production
Slow wave activity of hippocampus
The gyrus has connections with:
Amygdala and insula
Amygdala and ortbitofrontal cortex
Ventral striatum, putamen, and supplemental motor area
Cingulate gyrus
What receives input from the intralaminar nuclei and responds to pain
Cingulate gyrus
Two parts of amygdala
Dorsomedial
Ventral lateral
Dorsomedial aspect of Amygdala receive input from
Afferent from olfactory cortex
Ventrolateral aspect of amygdala receives input from
Afferent from visual, auditory, hippocampus and somatosensory cortex
Both the mediodorsal and ventrolateral portion of are involved with
Defense vs Attack postures
Central functions of the amygdala
Posture (instinctive)
Cognitive
Endocrine
Modulation of reticular formation
T/F: Amygdala is important for fear
True
