Welcome to the APPL601, Biological Bases of Behavior!

Your Host for the Semester

• Jim McConkey– MS/PMAC Biomedical Engineering from

Johns Hopkins• Specialties in neuroscience, medical imaging and

computer-guided surgery

– JMcConkey@UBalt.edu

Tonight

• Details about the course

• What are we studying?

• Organization of the nervous system

• Anatomy of the nervous system

Development of Psychology• Ideopathic model

– Spirits, demons, etc. cause pathologies.

• Mental model– Cognitive defects or faulty thinking cause

psychopathologies.

• Medical (biological) model– Psychopathologies are biologically driven.– They can be treated with drugs.

• Integrated model– The real world is somewhere in between.

Biological Bases of Behavior aka Biopsychology

aka Physiological Psychology

• The study of behavior and other psychological phenomena in terms of the development, functioning, and pathologies of the nervous system.

Biological Psychology

• How are behaviors controlled by the brain?

• What parts of the brain control which behaviors?

• How much control do humans have?

• How do psychoactive drugs work?

Neuroanatomy(structure)

Neurophysiology(function)

Biopsychology(behaviors)

Neuropharmacology(drugs)

Neuropathology(disease)

Neurochemistry

Neuroscience

Methods of Biopsychology

• Historical techniques: dissection, staining

• Surgical methods

• Electrical stimulation and measurement

• Pharmacological methods

• Genetic engineering

• Neuropsychological tests

• Non-invasive imaging techniques

Introduction to the Nervous System

Introduction to the Nervous System

• Nervous System– A system of nerves.

• Cells specialized for the translation and processing of information.

• Produce electrical and chemical activity.

• Connects and coordinates all parts of the body.

– A collection of specialized subsystems.

Divisions of the Nervous System

• Central Nervous System– Brain– Spinal Cord

• Peripheral Nervous System– Everything else

Divisions of the Peripheral NS

• Somatic– Receives sensory input from periphery– Conscious control of peripheral muscles

• Autonomic– Receives unconscious sensory input from organs– Unconscious control of movement and organs

Divisions of the Autonomic NS

• Parasympathetic– Mostly inhibitory– Controls “housekeeping” functions

• Sympathetic– Mostly excitatory– Controls “fight or flight” responses

Anatomy of the PNS

• Autonomic nerves– Parasympathetic nerves leave

the spinal cord at the cervical and sacral levels.

– Sympathetic nerves leave the thoracic and lumbar vertebrae.

• Somatic nerves– Enter and leave the spinal cord

at every vertebra.– Sensory nerves have bodies in

the dorsal root ganglia and ascend in the dorsal horns.

– Motor nerves descend in the ventral horns.

Recap of NS Organization

Nervous System

Central NS Peripheral NS

Parasympathetic Sympathetic

Somatic NS Autonomic NS

Organization of Nerves

• Nerves are organized in a tree-like fashion– Solitary neurons in the outermost periphery,

protected by an endoneurium.– Solitary neurons gather in small bundles called

fascicles, bound by a perineurium.– Fascicles gather with blood vessels in larger

bundles, bound by an epineurium.

Organization of Nerves

• Endoneurium wraps each neuron w/myelin.

• Perineurium wraps several neurons into a fascicle.

• Epineurium wraps a bundle of fascicles plus blood vessels.

Organization of Nerves

• Collections of neurons, grouped by function– CNS: tracts– PNS: nerves

• Neuron cell bodies tend to clump together:– CNS: nuclei (nucleus)– PNS: ganglia (ganglion)

Protection of the CNS

• The CNS is very important and very sensitive and is therefore well protected by:

– Thick bones– 3 layers of meninges– Cerebrospinal Fluid (CSF)– Blood-Brain Barrier– Circle of Willis – redundant blood supply

Protection of the CNS

• Skull– Thick, hard

bone– Over 1 cm

thick in places– Totally

surrounds and protects the brain

Protection of the CNS

• Meninges– Thick, fibrous

layers• Dura mater

– Periosteal– Meningeal

• Arachnoid mater• Pia mater

Protection of the CNS

• Cerebrospinal Fluid (CSF)– Mostly water– Shock absorber– Produced in choroid

plexus

Protection of the CNS

• Blood-Brain Barrier– Tight junctions

• pass O2, CO2, OH

– Carrier-mediated transport of

• glucose, AAs, ions

– Blocks• large molecules• many drugs and

toxins

Organization of the CNS

• The lower the brain level, the more primitive the more instinctive, and the less brain control.

• Pure reflexes occur in the spinal cord with no intervention from the brain.

• The older/lower parts of the brain have 2 layers of neurons. The newer parts of the brain (neocortex) have 6 layers.

Organization of the CNS

• Myelencephalon– Medulla oblongata (or just medulla)

• Contains nuclei which are part of the reticular formation and control:

– Arousal and attention

– Heart rate

– Respiration rate

– Cardiovascular smooth muscle tone

– Skeletal muscle tone

Organization of the CNS

• Metencephalon– Pons (=“bridge”)

• Part of reticular formation responsible for sleep and arousal

• Relay nuclei between cortex and cerebellum

– Cerebellum• Primarily responsible for coordinated

movements

• Receives all sensory input except olfactory

• Connected to pons via cerebellar peduncles

Organization of the CNS

• Mesencephalon– Tectum (=“roof”)

• Inferior (auditory) and Superior (visual) colliculi

• Responsible for audiovisual reactions

– Tegmentum (=“covering”)• Contains nuclei of the reticular formation

• Controls eye movements

• Red Nucleus – sends motor info from cortex and cerebelum to spinal cord

• Substantia Nigra – communicates with caudate and basal ganglia

Organization of the CNS

• Diencephalon (“2 brains”)– Surrounds the 3rd ventricle– Thalamus

• Two lobes• Major sensory transfer station• Many sensory nuclei

– Hypothalamus (=“beneath thalamus”)• Autonomic control center, four F’s• Hormonal control, direct and thru pituitary

Organization of the CNS

• Telencephalon– Cerebral cortex

• Two cerebral hemispheres

• Lateral ventricles (two)

• Corpus callosum/anterior commisure

• Limbic cortex– Involved in motivation and emotion

• Basal ganglia– Caudate nucleus, globus pallidus, putamen

– Involved in planned movement

Organization of the CNS

• Cerebral hemispheres– Lateralization, specialization per side– Left

• Verbal abilities

• Analysis and serial behaviors

– Right• Spatial abilities

• Synthesis

• Music, arts, emotions

Anatomical Directions

Posterior

(rear)

Anterior

(front)

Superior (top)

Inferior (bottom)

Dorsal = back

Ventral = front

Caudal = tail

Rostral = head

Lateral = side

Medial = center

Anatomical Terminology

• Brain topography terminology– A gyrus (gyri) is a bump– A sulcus (sulci) is a shallow groove– A fissure (fissures) is a deep groove

Gyrus GyrusFissure

Sulcus Sulcus

Anatomy of the Cortex

• Major anatomical landmarks– Longitudinal Fissure separates

hemispheres– Central Sulcus– Lateral (Sylvian) Fissure– Parieto-Occipital Sulcus

(internal)

Anatomy of the Cortex

• Major lobes of the cortex• Demarcated by fissures and sulci

– Frontal lobe - anterior to central sulcus• Thinking, planning, executive function

– Parietal lobe - posterior to the central sulcus• Association area

– Temporal lobe - inferior to the lateral fissure• Auditory function

– Occipital lobe - posterior of cortex• Vision

Anatomy of the Cortex

Anatomy of the Cortex

White Matter – has myelin sheath.

Gray Matter – no myelin. Cell bodies are here.

Cranial Nerves - 12 pairs

Spinal Pathways

• Spinal cord has two gray matter horns which contain cell bodies. The two sides are connected by the gray commissure, and are surrounded by white matter, which carries tracts.

• Dorsal horns receive sensory afferents.– Afferent somas external in dorsal root ganglia

• Ventral horns carries somatic motor efferents.– Efferent somas in ventral horns

Sensory Pathway

R