Brain Imaging Methods & Prenatal Development Lecture Notes (PDF)

Brain Imaging Methods & Prenatal Development Week 2, Lecture 2 January 17, 2024 Recap from Monday: What is the difference between cross sectional vs. longitudinal research design? What is a behavioural method of data collection? Brain Imaging Methods of Data Collection Methods of Data Collection Mag...

Brain Imaging Methods & Prenatal Development Week 2, Lecture 2 January 17, 2024 Recap from Monday: What is the difference between cross sectional vs. longitudinal research design? What is a behavioural method of data collection? Brain Imaging Methods of Data Collection Methods of Data Collection Magnetic Resonance Imaging (MRI) Measures anatomical and functional (fMRI) brain changes Methods of Data Collection Diffusion Tensor Imaging Measures brain structure Technique to estimate the location and orientation of white matter tracts by measuring the diffusion of water molecules 5 Methods of Data Collection Functional Near Infrared Spectroscopy (fNIRS) Measures brain function Oxygenated and deoxygenated hemoglobin have different light absorptive properties 6 Methods of Data Collection Electroencephalography (EEG) 7 Methods of Data Collection Event-related Potentials (ERPs) (Shimi et al., 2014) 8 Prenatal Development 9 Germinal Period: first 2 weeks after conception Zygote begins cell division as it travels down fallopian tube toward uterus. Cell differentiation Blastocyst: sphere with cells forming protective circle around inner cluster of cells from which embryo will develop Outer layer forms placenta Implantation: blastocyst burrows into wall of uterus 10 Embryonic Period: 3–8th week after conception All organs and major body systems form. Growth occurs in two major directions: Cephalocaudal development: head to tail Proximodistal development: midline outward Cells split into layers (ectoderm, endoderm, mesoderm), which form different body systems. Serious defects during this period often cause miscarriage, or spontaneous abortion (loss of fetus). 11 Fetal Period: 9th week to birth Appearance of bone, rapid growth, increasing complexity, and functionality of organs First trimester: Weeks 1–13 Spontaneous movement Second trimester: Weeks 14–26 Growth of lanugo and vernix caseosa Third trimester: Weeks 27–40 Increases in weight and length 12 Brain Development Begins at 3rd gestational week Differentiation of stem cells that later form the neural tube Fetal Period Neuron production, migration & differentiation. Childbirth Three Stages of Childbirth: Dilation Delivery Expulsion of placenta Cesarean section (C-section): surgical procedure that removes fetus from abdomen 14 Apgar Scale Quick & easy assessment of baby’s immediate health after birth 15 Infants at Risk: Low Birth Weight and Small-for-Date Babies Birth Weight: Low birth weight: less than 2,500 g (5.5 lbs) Very low birth weight: less than 1,500 g (3.5 lbs) Extremely low birth weight: less than 750 g (1 lb, 10 oz) Two types of low-birth weight infants: Preterm: born before due date Small for date: full term but experienced slow growth At risk for more problems Challenges in parenting low birth weight infants 16 On Friday …… Please read the sections on genetics