Limbic 1.0 Flashcards
(35 cards)
Suprachiasmatic Nucleus, SCN, and Sleep
SCN circadian rhythm - receives info from retina.
- if light, inhibits VLPO so you stay awake
Circadian Rhythm is susceptible to cytokines. Explain.
disrupts circadian cycle by breaking the circuit leaving the VLPO to be active during the day so you can sleep when you’re sick.
Sleep is regulated by the hypothalamus via which nucleus?
VLPO, the ventrolateral preoptic (remember those red and orange balls on the slide)… those two pathways that activate the thalamus and cortex (open sensory pathways).
VLPO inhibits these pathways that activate the thalamus and cortex inducing drowsiness.
What are some reticular pathways to the thalamus or cortex that initiate and maintain wakefulness?
Thalamus: (thalamus to cortex)
- cholinergic pontine pathways (PPT, LDT) most active during REM and waking
Cortex:
- monoaminergic pathways - NE, serotonin, dopamine
- cholinergic from basal forebrain nucleus
- orexin/hypocretin pathway from lateral hypothalamus
Humans have about how many hours of REM sleep a night?
2
The older you get the less _____ sleep you get, therefore, less deep sleep.
slow-wave sleep
stages 1-4 of sleep. EEG waves increase in amp and decrease in freq.
Non-REM
EEG similar to waking: low amp and high freq
REM
Which area of the Cingulate Gyrus coordinates several regions for precise recall of various aspects of episodic memory?
Retrosplenial
Limbic System and Memory: DECLARATIVE MEMORY. what is it? what parts of the brain are associated with it?
Hippocampus and Medial Temporal Lobe:
- the hippocampus encodes and consolidates episodic memories and projects to cortex (interconnects w prefrontal cortex).
- a fresh new memory lands in the medial temporal lobe.
also called explicit memory: episodic and semantic memory
What is episodic memory?
Declarative (explicit) Memory
- hippocampus
one of two the other being semantic memory
episodic:
- EVENTS!
- auto-noetic consciousness (with self in it)
“I had this episode where I threw my soup at the soup Nazi”
LIMBIC SYSTEM: cortical and subcortical regions are? try name a few!
Cortical:
- prefrontal
- cingulate
- insula
- parahippocampal gyrus
Subcortical:
- hippocampus
- amygdala
- ventral striatum/nucleus accumbens
Limbic System does what for us?
memory, motivation, emotions
Declarative Memory: what is semantic memory?
FACTS!
- prefrontal cortex, anterior temporal lobe
- non-contextual content of experience
- noetic consciousness
Different aspects of Declarative Memory (hippocampus and medial temporal lobe) are managed by distinct regions. Two systems are? What do they do?
Anterior Temporal System
- relates representations of specific entities to existing semantic concepts
ex. I see a coffee cup and think caffeinated beverage!
Posterior Medial System
- matches incoming cues about the current context to interactions among entities and the environment during a novel experience
ex. I see that 7-11 on the corner and know where I need to go, next door!, to get that coffee.
Limbic System and Memory: which part of the brain is associated with emotional type of procedural memory (implicit)?
Amygdala
- associative learning: classical and operant conditioning
Limbic System and Memory: what part of the brain is associated with working memory?
Prefrontal Cortex
Hippocampus (part of subcortical region)
Hippocampus role in the Limbic System?
Hippocampal Afferent pathway and Efferent pathway?
Stress & Memory (PRIMARY DECLARATIVE MEMORY ENCODER- CONTEXT)
Afferent: parahippocampal gyrus -> entorhinal cortex -> hippocampus
the hippocampus is the head of the seahorse and is affected last
Efferent:
from head to parahippocampal gyrus to wide areas of the cortex where memory is consolidated
The Reticular Formation plays a role in wakefulness. Where do the nuclei in the brainstem project to?
Sensory input enters?
wide areas of thalamus and cortex. medial nuclei project to brain and spinal cord for general modulation.
- sensory input enters raphe and lateral nuclei
“Ascending Reticular Activating System, ARAS”
Reticular Formation:
Nuclei of Raphe (medulla) to extensive cortical areas Neuromodulatory pathway uses which neurotransmitter for what?
Serotonin (5HT)
mood; sleep-wake cycles
- directly activate the cortex in waking
Reticular Formation:
Nuclei of Locus Ceruleus (pons) to cortex
neuromodulatory pathway uses which neurotransmitter for what?
NE
- attentional selectivity under stress
Reticular Formation:
Nuclei of ventral tegmentum (midbrain) [and substantia nigra] to prefrontal cortex and basal ganglia Neuromodulatory pathway uses which neurotransmitter for what?
Dopamine
promotes motivationally based behavior
Reticular Formation:
Nuclei of septum, nucleus basalis, and diagonal band of Broca to thalamus and extensive cortical areas Neuromodulatory pathway uses which neurotransmitter for what?
ACh
facilitate hippocampal and other cortical regions in memory and cognition
Generally, what does the Prefrontal Cortex do?
PFC can regulate its own catecholamine inputs how?
provide top-down control over attention, emotion, behavior
- through direct/indirect connections to reticular nuclei: NE via locus coeruleus and DA via substantia nigra and ventral tegmental areas
