Overview and Integration Behavioral, Cognitive, and Clinical Neuroscience Place Cells PET Techniques Normal Brain AD Brain Neuroscience from Historical and Biographical Perspectives Brain Hypothesis Neuron Hypothesis For a history of neuroscienece timeline: neurolab.jsc.nasa.gov/timeline.htm Site of Thinking: Heart, Ventricles, Brain Phrenology and Localization of Function Neurons as Units or a Neural Net Jan Purkinje Purkinje cell – first viewed in 1837 Cajal and Golgi – 1906 Nobel Prize in Physiology Santiago Ramon y Cajal Camillo Golgi Sherrington and the “Synapse” 1932 Nobel Prize in Physiology Lashley’s Search for the Engram in the 1920s After training, cortical lesions are made. Three different lesion locations are shown in red, blue, and yellow Rats are trained to run through a maze without entering blind alleys. Errors are associated with the size rather than the locus of the lesion. Donald Hebb and the Cell Assembly 1949 20th and 21st Century Advances Electrophysiology Imaging EEG Genetics CT Scan Human genome MRI Mouse genome Multiple Unit Recording PET Clinical genotyping Single Unit Recording SPECT Transgenic animals Tetrode Recording fMRI Knock-out animals ERPs MEG Comparative Neuroscience: Parallels in BrainBehavior Relationships Across Species Spatial Location Activation maps of 2 CA1 hippocampal place cells Fear Conditioning Associative Learning Eyeblink Classical Conditioning: Behavioral Parallels in All Mammals Including Humans Conditioned Stimulus (CS)–Unconditioned Stimulus (US) Pairings = Conditioned Response (CR) Genetics, Neurobiology, and Behavior Spatial and Temporal Control of Transgene Expression Doubly Transgenic Mice Region Specific Promoter + tTA responsive Promoter tTA-Gene _ Effector Gene Microarrays Method of examining changes in gene expression associated with event, drug, or disease Polymerase Chain Reaction Human Genotyping: Alipoprotein E Anatomical and Functional Neuroanatomy Tutorial: www.neuropat.dote.hu Sulci and Gyri in the Human Brain Ventral View of MTL Human Limbic System Individual Differences in Brains Neurons, Membranes, and Electrical Potentials Neuronal Membrane Ion Concentration Gradients Summation of EPSPs and IPSPs Ion Flow in 5 Phases of the Action Potential Synaptic Transmission and Brain Neurochemistry Transmission at the Synapse Brain Neurotransmitter Pathways Drug Effects on Neurotransmission Consciousness and Sleep EEG Stages in Wakefulness and Sleep Cortical Functions and Their Measurement: Vision as a Prototype Receptive Fields Dorsal (“Where”) and Ventral (“What”) Visual Streams in Human (PET) Dorsal (where) pathway shown in green and blue and Ventral (what) pathway shown in yellow and red serve different functions. (Courtesy of Leslie Ungerleider). Visual Attention: Color, Form, and Movement Activation remaining after divided condition subtracted from each of 3 focal attention conditions. Red boxes = color activation. Yellow boxes = motion activation. (Courtesy of Posner and Raichle). Developmental Neuroscience Halo response of an embryonic chick ganglion after incubation with nerve growth factor. (Courtesy of Rita Levi-Montalcini) Photographs of Human Fetal Brain Development Lateral view of the human brain shown at one-third size at several stages of fetal development. Note the gradual emergence of gyri and sulci. Eight Phases in Embryonic and Fetal Development at a Cellular Level 1. Mitosis/Proliferation 2. Migration 3. Differentiation 4. Aggregation 5. Synaptogenesis 6. Neuron Death 7. Synapse Rearrangement 8. Myelination 8 stages are sequential for a given neuron, but all are occurring simultaneously throughout fetal development Recovery from Aphasia: Imaging Neural Correlates Metabolic correlates of recovery in 2 patients. Perilesional regions near damaged left inferior frontal gyrus identified by single subject fMRI analysis. Rosen et al. (2000) Neurology, 55,1883-1894. Behavioral Remediation for Dyslexia: Imaging Brain Outcomes Phonological training in dyslexics who have little or no activation in left neocortical regions activated during reading in normal children results in increased activation in critical regions on the left AND increased activation in homologous right neocortex. Temple et al. (2003) PNAS, 100, 2860-2865. Emotion: Normal and Abnormal Papez Circuit (1937) Orbital Frontal Cortex and Impaired Social and Sexual Behavior After an on-the-job explosion blew a 13-pound tamping rod straight through Gage's head, the well-liked construction foreman remained conscious. He was able to talk and even walked to the cart that took him to Cavendish, Vermont where he was treated by Dr. John Martyn Harlow. Hypofunctionality and/or Lesions of Orbitofrontal Cortex Affect Emotion Fear Conditioning: Parallel Circuits in Humans and Rodents Neurobiology of Memory, Memory Impairment, and Dementia Normal Brain AD Brain Long Term Potentiation Formation of New Synapses Between Neurons Showing LTP Electron microscopic examination of synapses before and after undergoing LTP. Hippocampal neurons showing increases in Ca2+ also showed doubling of spines (From Toni et al., 1999). Synaptic Changes that Could Support Memory Forms of Long Term Memory Declarative •Semantic •Episodic Nondeclarative •Nonassociative (sensitization and habituation) •Procedural (Skill learning) •Priming •Simple Classical Conditioning Language and Executive Function Executive Function: Eclectic or Unified? In addition to Attention and Working Memory •Generating Ideas •Initiating •Inhibiting •Planning •Setting Goals •Regulating and Verifying •Temporally Ordering Dysfunction in Orbitofrontal Cortex Pseudodepression Pseudopsychopathy •Outward apathy and indifference •Immature behavior •Loss of initiative •Lack of tact and restraint •Reduced sexual interest •Coarse language •Little overt emotion •Promiscuous sexual behavior •Little or no verbal output •Increased motor activity •General lack of social graces Movement and Movement Selection Speech as an Example of Movement Selection PET Image of Speaking a Heard Word The Wernicke-Geschwind Model Norman Geschwind (1974) reintroduced Wernicke's language circuit in the mid-twentieth century, and the WernickeGeschwind model of brain and language function is still the basis for contemporary understanding The Wernicke-Geschwind Model is an Oversimplification Binder (2003) pointed out that the supramarginal gyrus along with the posterior superior temporal gyrus (including the planum temporale) and the posterior insula play a critical role in the selection and production of ordered phoneme sequences. Individual Variation in Lesion Sites of Broca’s, Wernicke’s, Conduction, and Global Aphasia Composite radioisotope brain scan for patients with each type of aphasia. Darker regions indicate areas where the lesions of many individual patients overlap. The isotope scans operate on the principle that the labeled compound can cross the blood-brain barrier in damaged tissue but not in healthy cortical regions. Dyslexia: Disruption in Posterior Brain Regions Neural systems for reading that are disrupted in dyslexic children. Shaywitz et al. (2002) Biol. Psychiat., 52, 101-110. Plasticity in Dyslexia as Well as Stroke Temple et al. (2003) PNAS, 100, 2860-2865. Rosen et al. (2000) Neurology, 55,1883-1894.