8.12. Integration of autonomic responses. Regulation of behavioral mechanisms. Motivation. Emotion. Flashcards
I. Autonomic NS integration
1. Explain The autonomic responses
The autonomic responses of the PARA and SYM nervous systems are closely integrated with both somatomotor and endocrine responses
I. Autonomic NS integration
2A. Where are autonomic nuclei located? Where does these autonomic nuclei lead to?
Located in the intermediolateral (IML) region of the spinal cord grey matter OR in brainstem nuclei (brainstem nuclei are only for PARA).
-> These autonomic nuclei lead to the preganglionic neuron axon fibers that normally synapse in a ganglion, then give postsynaptic fibers to a target cell
I. Autonomic NS integration
2B. How are autonomic nuclei controlled?
Primarily controlled by the hypothalamus, however, they may also be stimulated by pain receptors, thermoreceptors and visceroreceptors
I. Autonomic NS integration
2C. What do autonomic nuclei target?
They target the somatomotor system and endocrine glands and are responsible for some unconscious reflexes
I. Autonomic NS integration
2D. What is the role of pain receptors? (autonomic nuclei)
Pain receptors can activate a defensive reflex that includes both SYM response AND skeletal muscle activity
II. Cardiovascular reflex
2. What is the role of pressor center?
Pressor center: targets SYM neuron pathways targeting the heart, vessels, adrenal gland
II. Cardiovascular reflex
3. What is the role of DEpressor center?
Depressor center: inhibits the pressor center itself, inhibits the synapses between the pressor center and SYM nuclei, and also PARA innervation of the heart
III. Pupil reflex
1. Describe pupil reflex
- Basal activity is mostly sympathetic, meaning the pupils are dilated via information from the first 1st thoracic segment
- PARA response comes from light stimulation on the retina, which leads to pupillary constriction
III. Pupil reflex
2. Describe regulation of water uptake (hypothalamus?
- Hypothalamus is able to sense the need for water via circumventricular organ connections, where the BBB is incomplete
- These receptors are activated by high osmolarity, ANGII or peripheral receptor activation (low-pressure baroreceptors)
- Hypothalamus reacts by producing ADH as well as stimulating somatomotor activity that drives the animal to seek out water to drink
III. Pupil reflex
3. Describe Fight-or-flight reflex (hypothalamus)?
- Hypothalamus induce SYM activation + somatomotor responses and activation of the endocrine system (ACTH/glucocorticoid production)
- What is perceived as dangerous is involved in memory of your experiences, therefore, the hypothalamus works together with the limbic system and amygdala
IV. Non-cognitive behavior control
1. Which parts of the brain that are responsible for Non-cognitive behavior control?
- Paleocortex, diencephalon and brainstem are responsible for the non-cognitive behavior and emotion.
- It is a relatively ancient system and consists of hypothalamus, reticular formation, monoaminergic system and the limbic system
IV. Non-cognitive behavior control
2. Give some examples of non-cognitive behavior control
Examples of non-cognitive behavior control: include a wide array of mechanisms that are common in animals and/or humans:
- Control of alertness
- Mood
- Hunger, thirst
- Fear, rage, aggression
- Fight or flight
- Sexuality
- Self-defense and altruism
- Migration
IV. Non-cognitive behavior control
3A. What is the role of neural centers?
Neural centers: the brain controls these unconscious behaviors through a variety of neural centers and their neurotransmitter
IV. Non-cognitive behavior control
3B. What are the 4 important neural centers?
- Reticular formation
- Locus ceruleus
- Substantia nigra
- Raphe nuclei
IV. Non-cognitive behavior control
3C. What is the role of reticular formation?
Reticular formation: acts as filter for the sensory system and modulates sensory pain signals, sometimes to increase/decrease their sensation. It also creates excitatory signals up to the cortex to affect motor action, and inhibitory signals that can induce sleep
IV. Non-cognitive behavior control
3D. What is the role of Locus ceruleus?
- It is located in pons and produces NE.
- This center aids in alertness and excitatory control.
- Locus ceruleus is responsible for REM sleep and target of many drugs such as cocaine + amphetamine
IV. Non-cognitive behavior control
3E. What is the role of Substantia nigra?
Substantia nigra: located in mesencephalon and produces dopamine. Dopamine can be both inhibitory (D2 – G1) and excitatory (D1 -G2)
IV. Non-cognitive behavior control
3F. What is the role of Raphe nuclei?
- Raphe nuclei: located in pons + medulla.
- Nuclei produce serotonin and send efferentations to diencephalon, cortex and spinal cord.
- The nuclei is used to modulate pain sensation and is generally inhibitory
V. Limbic system
1. What is another name of lambic system?
paleocortex – ancient part of brain
V. Limbic system
2. What are the features of limbic system?
- Responsible for feeling of rage, fear, panic, vigilance, feelings of being lost/lonely,
sexuality, reward, punishment, regret and care - It is the emotional brain and consists of many parts that make up a ring structure
bordering the cortex
V. Limbic system
3A. What is the role of hypothalamus in limbic system?
The hypothalamus is involved in the limbic system, as well as the control center of all vegetative functions that accompany affection
- Lateral hypothalamus: increased activity, rage and fighting feelings
- Ventromedial: tranquility, safety
- Anterior: sexuality
- Paraventricular: oxytocin production, erections
V. Limbic system - Hypothalamus
3B. What is the role of lateral hypothalamus?
increased activity, rage and fighting feelings
V. Limbic system - Hypothalamus
3C. What is the role of Ventromedial hypothalamus?
tranquility, safety
V. Limbic system - Hypothalamus
3D. What is the role of Anterior hypothalamus?
sexuality
V. Limbic system - Hypothalamus
3D. What is the role of Paraventricular hypothalamus?
oxytocin production, erections
V. Limbic system
4. What is the role of Hippocampus, dentate gyrus?
responsible for long-term memory and affections
V. Limbic system
5. What is the role of Amygdala?
- Motor control of rage, reward, escape, pleasure + involuntary actions such as licking, chewing, eating etc.
- There is some SYM and PARA reactions including BP, HR, GI-motility, secretion, defecation, pupillary reactions, erection control => basically everything affects everything
VI. Limbic circuits
1. How are Limbic circuits activated?
Activated by sensory input or smell (among many things), and this activates the thalamus or amygdala to begin the circuit that transcends to the prefrontal cortex or cingulate gyrus
VI. Limbic circuits
2. Describe Papez’ circuit
- Activated from the cingulate gyrus
-> parahippocampla gyrus
-> entorhinal cortex
-> subiculum
-> fornix
-> mamillary bodies
-> thalamus
-> back to cingulate gyrus - The output of the limbic circuits includes hormonal release and motor responses, whether they are conscious or unconscious
VI. Limbic circuits
3. Make a schematic diagram of Papez’ circuit
