Developmental Neuropsychology Lectures 2024-2025
Lecture 1: Introduction brain and plasticity
Introduction to the course
• 1 mandatory seminar, linked to the assignment
• All information on the assignment will be uploaded on nov 29
• Book; developmental neuropsychology
o Addition of articles on topics not covered in the book
• Assessment
o Assignment 40%
▪ Deadline 10th of January
o Exam 40%
▪ 40 multiple choice questions and 2 open questions
▪ Information from the lectures are important
▪ The book:
• Not the theoretical models, unless discussed in the lectures;
summaries and conclusions, not the details; reading guide!
▪ January 24th 2025 Olympus
Developmental neuropsychology
The study of brain/behaviour relationships with the context of an immature but rapidly
developing brain and the implementation of knowledge gained into clinical practice.
• Other terms: child neuropsychology, paediatric neuropsychology
Difference developmental cognitive neuroscience; focuses on normal cognitive functioning,
whereas developmental neuropsychology focuses more on abnormal development.
Assumptions
• There is a significant difference between the consequences of disturbing a developing
brain and damage to an adult brain.
Adult neuropsychology:
• The brain is static, tightly organized, less plastic
• There is a one-to-one relationship between structure and function
• Symptoms (= function impairment) can be related to underlying neurological defect
(= localization/network)
Developmental neuropsychology:
• The brain is dynamic
• Changes in brain development are closely related to changes in behavioural, social
and cognitive development
, • Symptoms and the underlying neurological defect are not clearly related
o The same brain damage can lead to different symptoms in childhood
o Also: the same symptoms might point to quite different neurological causes
• It all depends on the timing of the brain damage, social environment and factors
within the child
• Brain development is a dynamic process in which many factors are involved:
biological, cognitive, social-emotional, developmental and environmental
• Therefore, later outcomes will be difficult to predict
• There is a need to address the ‘totality’ of the child
Neuroanatomy
• Brian tutor app
Anatomical development
Just after fertilization rapid fire of cell division
• Zygote: just 2 cells
• Morula: clump of cells
• Blastocyst: inner cell mass, where the embryo further develops
Development of CNS
• 14 days after fertilisation, the inner cell mass of the blastocyst develops into a
structure with 3 layers
o Ectoderm: skin, central nervous system
o Mesoderm: skeleton, muscles
o Endoderm: inner layer, intestines
• Neurulation or neural induction
• The neural plate is created from the ectoderm
• 3rd-4th week; neural tube.
• At this stage, neural development can already be disturbed
,Closure defects
• Anencephaly (closure defect on the head end of the neural tube); fatal
• Spina bifida (incomplete closing of the backbone around spinal cord. Often in
combination with hydrocephalus
Brain vesicles
• Telencephalon (cortex)
• Diencephalon (thalamus and hypothalamus)
• Mesencephalon (midbrain)
• Metencephalon (cerebellum and pons)
• Myelencephalon (medulla)
Most of the development takes place before birth
Development of the nervous system
Development of different structures at different times (but overlapping)
• Spinal cord & brain stem
• Amygdala, cerebellum, hippocampus
• Thalamus, basal ganglia
• Cerebral cortex (posterior to anterior)
Histological development
• Cell proliferation, cell migration, cell differentiation and growth, selective cell death
and synaptic pruning, myelinisation
Proliferation (weeks 6-18)
• About 250.000 new cells a minute!
• Proliferation zones: where new cells are made
o Ventricular zone (all cell types)
o Subventrical zone (especially front of the cortex)
• Progenitor cells
o Neuroblast -> neuron
o Glioblast -> glial cell
,Problems during cellular development
Disorders in cell proliferation (2-5 months)
• Causes
o Genetic
o Trauma (infection, fetal alcohol syndrome, radiation, Zika virus)
• Neural effects
o Microcephaly (cell division stops prematurely) -> brain too small
o Megalencephaly (overproduction of cells) -> brain too large
• Functional effecs
o Motor and/or intellectual impairments, learning problems, epilepsy
Histological development
Migration
• Passive migration (thalamus, brain stem)
o Newer cells being made push out older cells to the place where they need to
function. Older cells outside/ top layer, newer cells inside/bottom layer
• Active migration (cortex)
o Active movement of neurons, glial cells make a path that neurons can follow
to the correct location
o Characterized by latest/newest neurons moving to layers on the outside,
opposite of passive migration
Problems during cellular development
Disorders in cell migration
• Causes
o Genetic, toxic substances, viral infection, intrauterine damage
• Neural effects
o Lissencephaly (smooth cortex, no sulci or gyri)
o Schizencephaly (subnormal clefts in cortex, cell layers not clearly defined)
o Polymicrogyria (multiple small gyri, neurons in abnormal locations)
o Agenesis (absence of the corpus callosum)
o Dysplasia (heterotopia) (abnormal cell layer structure/ cells in the wrong
place)
• Functional effects
o Epilepsy, motor and/or intellectual impairments, learning problems,
behavioural problems
o Severity varies within and between syndromes
, Histological development
Differentiation
• Growth of dendrites and axons
• Formation of synaptic connections (synaptogenesis)
Cell death and synapse elimination
Brain development is characterised by overproduction (rise) and death (fall) of neurons and
synapses.
• Apoptosis or programmed cell death
• Pruning = synapse elimination depending on experience, hormones and genes
• Experience
o Experience-expectant synapses (sensitive periods)
o Experience-dependant plasticity (enriched environment)
• Use it or lose it principle
• Neurons that fire together will wire together
o Simultaneous activity of neurons strengthens connections
Adult brain: less connections, but efficient network.
Disorders in synapse formation and pruning
• Causes
o Genetic, toxic substances, problems during cell migration and cell
differentiation, stimulus, experiences
• Effects
o None (synapses are flexible)
o Abnormal brain development
