Brain Regions/Functions – Hindbrain, Midbrain, and Subcortical Forebrain StructuresBrain Regions/Functions – Hindbrain, Midbrain, and Subcortical Forebrain Structures

Physiological Psychology and Psychopharmacology

Hindbrain Structures

located just above the spinal cord and includes the medulla, pons, and cerebellum

Medulla

It’s responsible for the involuntary mouth and throat movements involved in swallowing, coughing, and sneezing, and it regulates a number of functions that are essential for survival including respiration, heart rate, and blood pressure. Brain injury and certain diseases and drugs (especially opioids) can disrupt the functioning and result in death.  

Pons

It connects the two halves of the cerebellum and helps coordinate movements on the two sides of the body, and it relays messages between the cerebellum and cerebral cortex. It also plays a role in respiration and the regulation of deep sleep and rapid eye movement (REM) sleep.

Subcortical Forebrain Structures

These structures include the hypothalamus, thalamus, basal ganglia, amygdala, and hippocampus.

Hypothalamus

It maintains the body’s homeostasis and regulates functions critical to survival through its influence on the autonomic nervous system and pituitary gland. It also contributes to emotions, memory, and circadian rhythms. It contains the mammillary bodies, which play a role in memory, and the suprachiasmatic nucleus (SCN), which serves as the body’s biological clock and regulates the sleep-wake cycle and other circadian rhythms.  

Hypothalamus

• Influences the pituitary gland in two ways:

  • 1.produces hormones that stimulate or inhibit the release of hormones produced by the anterior pituitary

  • 2. sends oxytocin and vasopressin (also known as antidiuretic hormone) to the posterior pituitary, which stores these hormones and then secretes them into the bloodstream at appropriate times.

Thalamus

“relay station” because it receives and then transmits sensory information to the cortex for all of the senses except smell. It also plays an important role in the coordination of sensory and motor functioning, language and speech, and declarative memory.

Basal Ganglia

Consist of the caudate nucleus, putamen, nucleus accumbens, and globus pallidus. Involved in the initiation and control of voluntary movements, procedural and habit learning, cognitive functioning (e.g., attention and decision-making), and emotions.

Limbic System

Responsible for emotion, motivation, and memory. The amygdala, cingulate cortex, and hippocampus have traditionally been identified as its primary structures.

Amygdala

It is responsible for processing and regulating fear, anger, anxiety, joy, and other emotions; recognizing fear and other emotions in facial expressions; and attaching emotions to memories.

Cingulate Cortex

It plays a role in motivation, memory, and emotions, including emotional reactions to pain. People with damage to the cingulate cortex experience pain but are not emotionally distressed by it.

Hippocampus

It’s responsible for transferring declarative memories from short-term to long-term memory and plays an important role in spatial memory.

Midbrain Structures

connects the hindbrain to the forebrain and includes the reticular formation and substantia nigra.

Reticular Formation:

Consists of a network of neurons that extend from the medulla into the midbrain. It’s involved in a variety of functions including regulation of muscle tone, coordination of eye movements, and control of pai

Substantia Nigra

Plays a role in reward-seeking, drug addiction, and, through its connection to the basal ganglia, motor control. Degeneration of dopamine-producing cells in the —— is a cause of the slowed movement, tremors, rigidity, and other motor symptoms associated with Parkinson’s disease.

Reticular Activating System (RAS)

The ___ mediates consciousness and arousal, controls the sleep/wake cycle, and alerts the cerebral cortex to incoming sensory signals. Lesions in the __ can cause a comatose state, while direct electrical stimulation or stimulation by sensory input can awaken a sleeping person and cause an awake person to become more alert.