kolbintro6e_lectureslides_ch07
Introduction to Brain and Behavior Measuring and manipulating brain and behavior Methods include:
Brain's electrical activity measurement: Involves techniques such as EEG and single-cell recording to observe neural activity in real-time.
Anatomical imaging techniques (CT, MRI): CT scans utilize X-rays for structural imaging, while MRI provides high-resolution anatomical images through magnetic fields.
Functional brain imaging: Techniques like fMRI and PET scans measure brain activity by detecting changes in blood flow and metabolic rates.
Chemical and genetic measures: Methods like microdialysis and cerebral voltammetry assess biochemical changes in the brain associated with behavior.
Animal-based research methods: Employ animal models to study complex behaviors and neurological processes in a controlled setting.
Measuring and Manipulating Brain and Behavior Neuropsychology Examines the relationship between brain function and behavior, especially in humans. Origins traced to Paul Broca's discovery linking left frontal lobe damage to language issues. Neuropsychology utilizes advanced imaging, neuroanatomical measurements, and behavioral analysis to understand cognitive deficits arising from brain lesions.
Techniques in Behavioral Neuroscience Early Techniques
Histological Techniques: Involve postmortem brain sectioning, and tissue staining to reveal structural differences related to behavior, allowing for correlations between anatomy and function.
Behavioral Neuroscience Objective: Aims to study the biological bases of behavior, integrating both human and animal models, while facing challenges in measuring and interpreting both normal and abnormal behavioral patterns.
Neuropsychological Testing Assessing memory disturbances caused by damage to the temporal lobes reinforces the concept that memory is multi-faceted; hence various types of memory functions must be tested separately to gain comprehensive insights.
Animal Behavioral Analysis Rodent Behavioral Tasks: Various tasks are employed to evaluate spatial memory using external cues.
Types of Tasks:
Place-learning: Tests spatial navigation abilities.
Matching-to-place learning: Evaluates memory recognition based on spatial locations.
Landmark learning: Assesses the use of prominent external cues for navigation.
Skilled Reaching: Rats are trained to retrieve food while analyzing their movement patterns to understand neurological impairments.
Modifying Brain-Behavior Interactions Researching how changes in the brain (e.g., lesions) influence behavior. Historical examples include Karl Lashley’s studies on memory location, leading to understanding the complexities of memory storage in the brain.
Ablation: Removal of specific brain tissue can yield substantial behavioral changes, as seen with H.M., who developed amnesia after hippocampus removal, providing critical insights into the brain's memory systems.
Brain Stimulation Techniques Wilder Penfield's pioneering work in electrical brain stimulation aimed to map functional areas in the brain, linking specific regions to motor and sensory functions.
Deep-Brain Stimulation: Low-voltage electrical currents are used therapeutically to manage conditions like Parkinson’s disease and depression, helping to alleviate symptoms or restore lost functions.
Drug Manipulations Administering drugs to explore their effects on brain activity and behavior enables scientists to dissect the pharmacological underpinnings of complex behaviors. These techniques allow targeted biochemical manipulation of brain functions to validate hypotheses regarding behavior.
Genetic Manipulations The advancement of techniques like optogenetics allows researchers to control genetically modified proteins using light to observe changes in neural activity and corresponding behavior.
Chemogenetics: This technique utilizes synthetic drugs to activate engineered receptors within the brain, enabling selective influence over specific neural circuits and behaviors.
Measuring Electrical Activity Major Techniques:
Single-cell Recording: Provides precise measurements of action potentials from individual neurons, elucidating their role in behavior.
EEG: Records electric activity across populations of neurons, revealing brain wave patterns associated with different states of consciousness and cognitive processes.
Event-Related Potentials (ERPs): Offers insights into cognitive processing through brain responses that are time-locked to specific stimuli.
Magnetoencephalography (MEG): Measures magnetic fields generated by synchronized neural activity, providing high spatial and temporal resolution imaging of brain function.
Anatomical Imaging Techniques:
CT Scans: Use X-ray technology to produce cross-sectional images of the brain, helping to identify structural anomalies.
MRI: Produces high-resolution images of brain anatomy through magnetic resonance, allowing for detailed analysis of brain structure.
Diffusion Tensor Imaging (DTI): Imaging technique that visualizes neural pathways by tracking the movement of water molecules, offering insights into white matter integrity.
Magnetic Resonance Spectroscopy (MRS): Measures concentrations of specific brain metabolites, helping to detect metabolic abnormalities associated with various psychiatric and neurological disorders.
Functional Brain Imaging:
fMRI: Measures changes in blood flow associated with neural activity, providing insights into brain functions and connectivity.
PET Scans: Utilize radioactive tracers to measure metabolic activity and blood flow in the brain, aiding in the diagnosis of abnormalities.
Resting-State MRI (rs-MRI): Assesses functional connectivity among brain regions during a resting state, enhancing understanding of neural networks when subjects are not engaged in specific tasks.
Chemical and Genetic Measures:
Microdialysis: A method to collect biological samples from the extracellular fluid for chemical analysis, improving insight into neurotransmitter dynamics during behavioral tests.
Cerebral Voltammetry: Allows real-time monitoring of neurotransmitter levels in the brain as behaviors are expressed, enhancing understanding of the chemical basis for behavior.
Measuring Genes and Epigenetics:
Genetic research enhances understanding of behavior through twin studies and investigations into gene variations that contribute to cognitive functions.
Brain-Derived Neurotrophic Factor (BDNF): Plays a crucial role in neural plasticity and memory formation; variants have been associated with memory performance.
Epigenetic Factors: Environmental influences on gene expression can result in lasting effects across generations, impacting behavioral outcomes significantly.
Animal Models in Research Importance of adhering to ethical guidelines in animal experimentation to ensure humane treatment and compliance with regulatory standards governing animal use in research settings. Successful animal models, like the Kyoto SHR rats, provide crucial insights into human cognitive dysfunctions such as ADHD, highlighting the potential benefits of animal research in understanding complex human behaviors.