Overview of Behavioral Anatomy & Addiction

The Nervous System nervous system is responsible for communication between us and environment among regions of the body coordinates and integrates information regulates activity; maintains homeostasis memory & consciousness Histology slide of some brain tissue

CNS PNS Sensory Division afferent sensory nerves to CNS Motor Division efferent motor nerves to muscles & glands Autonomic NS involuntary heart, smooth muscle, glands Somatic NS skeletal muscle

A nerve cell showing dendrites and an incoming axon. D A D

(Another) histology slide illustrating the physical layout of some nerves in the brain.

Some Important Parts of the Brain Cognitive area

Limbic (another very important) System of the Brain The limbic system is responsible for generating our emotional feelings (pleasure, frustration, anger) based on our cognitive interpretation of our environment

Substantia nigra Caudate Putamem Globus Pallidus Ventral tegmental area Locus coeruleus Basal Ganglia is part of the limbic system

Our sensory nerves inform our brain about our physical environment

Kinesthetic Perception Sensory areas of the brain receive input from nerve fibers which originate from different types of receptors (touch, visual, auditory, pain, taste). Sensory nerves originating from Pacinian corpuscles in the skin (mechanoreceptors) respond to touch. Sensory nerves originating from proprioceptors in the joints respond to “angle-specific pressure” A-delta nerves originating from free nerve endings (Noci receptors) respond to tissue damage.

Primary (SI) and secondary (SII) sensory cortex involved with the localization of pain Anterior portion of insular is most likely concerned with pain perception

All sensory information is relayed throughout different parts of the brain and our conscious interpretation of the stimuli generates a physical and emotional response which we “feel”: body/joint position, body and/or limb movement, well- being, nausea, pain … happy, sad, frustration, disappointment, joy, ecstasy, anger … Our CNS response to stimuli also includes (selective) changes in the (autonomic) sympathetic and parasympathetic nerve pathways; selective changes based on our interpretation of the stimuli.

Sympathetic N.S. Thoracic, Lumbar motor nerves –synapse close to spinal cord Fight or flight –preservation of life –heart & skeletal muscle stimulated  blood pressure  metabolism  brain activity –vegetative functions inhibited

Parasympathetic N.S. craniosacral motor nerves –synapse in wall of organ vegetative functions –internal housekeeping, recovery, rest  G.I. activity digestive organs –inhibit brain & muscle

Learning and memory play a very important role in how we develop behaviors

Memory A “memory” is not a discrete location in the brain made up of a cluster of cells which are independent of other cells. A “memory” is actually comprised of a “pattern” of nerve-cell activities made up of interconnected nerve cells which are scattered throughout the cerebral cortex. These cells are in turn interconnected to all other brain cells.

Memory/Learning We do not remember facts as discrete pieces of independent information. We have memories of “facts” only in association with other memories. We develop new memories only in association with existing memories.

Memory/Learning New memories are created by rearranging existing patterns of activated nerve cells into new patterns of activity. This process demands synthesis of new proteins in “some” nerve cells to modify their ability to be activated by other nerves and thereby create a new patterns of activation.

Learning Parts of the brain that are important for learning.

Learning Hippocampus coordinates environmental stimuli and activates existing memory.

Learning New memory is constructed based on novel stimulus in comparison to existing memory. “Strength” of the memory is dependent on the frequency and strength of the neural activity.

Learning & Memory The new memory is activated either through the “novel” stimulus or through the associated memory. We remember facts as pieces of “information” in relation to other pieces of “information” which in turn are related to other …

Memory / Behavior Sensory memories of physical movements are stored as patterns of neural activity in the cerebellum and are developed in much the same way as factual memories.

Memory / Behavior All sensory inputs are coordinated by reticular formation and basal ganglia and transmitted to frontal cortex. Sensory input is unconsciously compared to sensory memory and adjustments are made “as-you-go”. Simultaneously, conscious image is compared consciously to conscious memory of what we should look like while we do it and we make conscious adjustments to mimic the conscious memory of the skill. Integration of conscious and subconscious adjustments based on conscious and subconscious memories of the performance result in the actual performance.

The most basic connection between behavior and memory is that we desire to perform behaviors which produce responses that we want….if we can’t remember that a particular behavior resulted in a desirable outcome, there is little chance we will seek out to repeat the same behavior. In addition, if a particular behavior results in an unpleasant experience, there is a strong likelihood that we will avoid that behavior. On the other hand, if a behavior is not particularly pleasant, but does result in a highly desirable outcome, there is a high likelihood that the unpleasant behavior will be continued in order to get the pleasant payoff. Memory, Learning & Behavior

Memory / Learning / Behavior With greater pleasure, reinforcement can be developed more easily and quickly. With greater activation of the memory & learning pathways during the behavior, the easier and faster the learning. With more important desired behaviors, there is greater craving in their absence.