INTRODUCTION TO PSYCHOBIOLOGY

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INTRODUCTION TO PSYCHOBIOLOGY
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What is Psychobiology?

• it is the study of the neural basis of
  behaviour, but this colourless definition does
  not do justice to the wealth of scientific
  expertise that it incorporates.
• Sahagal (1993)

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Psychobiology by Any Other Name

• Biopsychology
• Behavioural neuroscience
• Behavioural biology

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Subdivisions of Psychobiology

• Physiological psychology
• Psychopharmacology
• Neuropsychology
• Psychophysiology
• Comparative psychology
• Cognitive neuroscience
• Behavioural genetics

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Human vs. Animal Research

• Human
• Relatively cheap
• Insight
• Extrapolation not required

• Animal
• Expensive
• Controlled environment
• Permit procedures that are regarding as unethical
  in humans
• Behaviour less complex
• Requires extrapolation

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Animals (Scientific Procedures) Act (1986)

• License
• Institute
• Project
• Person

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Validity of Animal Models of Behaviour

• Willner (1991) stated that, models are tools.
  As such, they have no intrinsic value the value
  of a tool derives entirely from the work one can
  do with it. Conclusions arising from the use of a
  simulation of abnormal behaviour are essentially
  hypotheses that must eventually be tested against
  the clinical state. An assessment of the validity
  of a simulation gives no more than an indication
  of the degree of confidence that we can place in
  the hypothesis arising from its use.

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Three Facets of Validity

• Taken from the world of psychometric testing, an
  animal model should exhibit
• Predictive validity
• Face validity
• Construct validity
• Willner (1984)

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Genetics

• Darwin
• Mendel
• Crick and Watson

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Evolution

• Darwin
• Survival of the fittest
• evidence based
• Descent through modification

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Mendelian Genetics

• Mendel a monk
• Pea traits
• Can be applied to humans
• Dominant traits
• Recessive traits

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Seed Colour
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Chromosomes

• 23 matched pairs
• Genetic material passed on to offspring
• Cellular division
• Mitosis
• Meiosis

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Meiosis
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Mitosis
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DNA

• Each chromosome contains a double stranded
  molecule
• deoxyribonucleic acid (DNA)
• Each strand of DNA is a sequence of nucleotide
  bases attached to a chain of phosphate and
  deoxyribose

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DNA
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Replication

• Replication is critical for mitosis
• The DNA strands unwind
• The exposed nucleotide bases attract
  complementary bases form the fluid of the nucleus
• Two DNA molecules that are identical are created
• Mutations of this process can occur

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Replication
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Protein Synthesis

• The genetic code produces amino acids
• Making protein and polypeptides
• Transcription

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Transcription

• Code taken outside nucleus
• mRNA
• RNA is like DNA
• mRNA attaches itself to ribosomes in the cell
  body
• The ribosomes move along the strand of mRNA and
  read the code

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Transcription