Download doc Lectures 1

PSYC342 – Hormones and Behaviour
Prof. Jens Pruessner
TA Hours: Johanna Harrison Mon 330-430pm in ST/BIO W8/35
Midterm on March 3rd in Leacock 132 at 6pm
January 4th: Lecture 1
Introduction
Course structure and assessments.
Exams will be multiple choice and essay questions.
Top Journals: Nature, Science, Cell.
The Journal Impact Factor: e.g. 30 = approximately 30 citations a year
The H-Index: E.g. Total 20 Publications. First = 30. Second = 25. Third = 18 . How many
publications have been sited equally? Essentially a mean of the Journal Impact Factor.
Peer Review Criteria: Novelty, Impact, Accuracy and Sound Science.
Shortcomings of Peer Review: Personality, politics.
Editors are often hard pressed to find reviewers. They must be knowledgable of the field or go by
suggestions of the author. The editor of the journal is responsible for it's peer review.
First reading from the course pack is about peer review and the statistics of favourable reviews if
reviewed by author recommendations or editors choice.
Online only journals – e.g. PloS ONE: (Public Library of Science) Forums are attached to each
paper forever. PloS ONE is the third largest scientific journal in the world (by volume). It is the
largest open access journal in the world.
January 6th: Lecture 2
The Disappearing Male: Movie screening about chemical pollution and it's effect on males.
Last Class Summary: Scientific knowledge is communicated via publications, either in print or
online journals. Journals are measured via the journal impact factor. Traditional medium for
journals is print but we are switching to online journals (e.g. PloS ONE). Consequence is that
traditional journals must update themselves to the new medium.
Methods in Research and Academia
The Scientific Method is necessary if you want to publish. What are the terms of the method?
Formulate a theory – Gather evidence – formulate a theory... It's a cycle. Be precise, be skeptical
and rely on empirical evidence.
Theory: an organised system of assumptions designed to explain phenomena and their
interrelationships. Hypotheses: attempts to predict or account for a set of phenomena; specifies
relationships among variables and are empirically tested. Operational definitions: define terms in
hypotheses by specifying the operations for observing and measuring the process or phenomenon.
Skepticism: Do not except ideas simply on faith or authority. Treat conclusions, old and new, with
caution. Finally, scientists relies on empirical evidence to determine whether a hypothesis is true.
Karl Popper's 'critical rationalism'
Principle of Falsifiability: a scientific theory must make predictions specific enough to possibly
disconfirm the theory. The theory must predict not only what will happen, but also what will not
happen.
Descriptive Studies: studies using methods that yield descriptions of behaviour but not necessarily
causal explanations e.g. case studies (more commonly used by clinicians, occasionally by
researchers e.g. HM – lost ability to form new memories), naturalistic observations, surveys,
psychological tests.
E.g. of case study pitfall: Clever Hans was a trotter horse that was claimed to have been able to
perform arithmetic and other intellectual tasks. However this was all coincidence, the trainer would
move his body whenever the number of foot stamps reached the correct number. This was exposed
by removal of the trainer in experiments designed to remove the possibility of the experimenter
effect.
Observational studies can be naturalistic or laboratory observations. Naturalistic observations:
provides descriptive data about behaviour uncontaminated by outside influences. However it is
affected by observer bias and participant self-consciousness.
Psychological tests: Used to measure and evaluate personality traits, emotional states, aptitudes, etc
and are known for their standardisation (compared to norms established by a mean of a large
group of people), validity (the ability of a test to measure what it was designed to measure) and
reliability (consistency).
Surveys: Relies on volunteers. Volunteer Bias: those who participated may differ from those who
did not.
Correlational Studies: Descriptive studies that look for a consistent relationship between two
phenomena. Stats range from -1 to +1. Cannot infer causal relationships.
Ice cream causes murder statistic: Correlational data, not causal. There is a mediating variable
which was found to be heat in this study.
Experiments: a controlled test which discovers one variables effect on another. All confounding
variables are controlled e.g. random assignment, placebos. Independent/dependent variables.
Water memory: Because of the reported therapeutic powers of homeopathic remedies, Jacques
Benveniste theorised that water can 'remember' substances. However double blind studies did not
report this effect.
Most commonly used inferential statistics are significance tests.
January 11th: Lecture 3
Autonomic Nervous system: Involuntary. Divided into Sympathetic (fight or flight) and
parasympathetic nervous system (digestive/rest). These two systems inhibit each other. When one is
activated, the other is inhibited.
Kluver Bucy Syndrome: Bi lateral damage to the anterior temporal lobes leading to part destruction
of hippocampus and amygdala which are both engaged in emotional regulation. Example of the
importance of the regulation of emotion. Pronounced docility – absence of fear. Hyper-orality.
Hyper-sexuality. Visual Agnosia (inability to recognise people).
Broca's and Wernicke's area are in the left hemisphere if you are right handed 98% of the time.
These two areas are associated with speech. If you are left handed they are in the right hemisphere
90% of the time.
Oliver Sachs wrote a book about a patient with damage to Broca's area. He could understand but
could not produce meaningful speech.
Neurotransmitters. Normal function. Disorder associated with malfunctioning.
Acetycholine (+/-): Movement, Memory. Alzheimer's Disease.
Dopamine (+): Movement, reward. Parkinson's disease, Schizophrenia.
Adrenaline/noradrenaline (+): Sleep, learning, mood. Depression.
Serotonin (-): Mood, appetite, aggression. Depression.
Glutamate (+): Memory. Neuron loss after stroke.
GABA (-): Movement. Severe anxiety, Huntington's disease, epilepsy.
Patients with damage to the corpus callosum have split-brains. You can study these patients by
showing them objects to their left and right eyes. Their eyes are controlled by the contralateral
hemisphere.
Basal Ganglia: Composed of the striatum (caudate and putamen) and the globus pallidus. It is
related to motivation, reward, movement and motor control.
Midbrain:
Tectum and Tegmentum: Roof and covering.
Superior/inferior colliculus.
Midbrain plays a role in sensory processing, attention, arousal and sleep.
Hindbrain:
Cerebellum
Pons
Medulla Oblongata
Neurotransmitter Pathways:
Substantia Nigra to Striatum pathway: Nigrostriatal pathway.
Mesolimbic and Mesocortical pathways.
January 13th: Lecture 4
Overview of the Hormone and Endocrine System
Review: The nervous system is divided into sections, some of which are older due to the
evolutionary process. The neocortex is involved with intellect, cognition and reasoning and is one
of the newest parts of the brain. The nervous system (NS) is hierarchical.
Neurotransmitters (NT) are used because of up and down regulation of activation, for it's failsafe
mechanism, for it's use in development and learning and because it offers a centralised control.
MS. Zamboni. Caused by impaired veinous drainage in the brain (vascular hypothesis).
Inflammatory disease (traditional hypothesis). RCT (randomised control trials) are being conducted
now to explore MS more.
The Endocrine System
Endocrine means 'the internal secretion of a biologically active substance'. The system is
hierarchical, some glands control other glands.
Hormone Definitions
A chemical messenger effective in minute quantities.
Synthesised in ductless glands.
Secreted into and transported by blood.
Acts on receptors located far away from synthesis.
Exerts a specific regulatory effect on target cell.
However... there are Exceptions
Some hormones aren't synthesised in ductless glands.
Hormones sometimes act as neurotransmitters (paracrine function)
They can influence the cells that released them (autocrine function)
Hormones can have generalised effects, or different effects depending on the specific receptor type.
Still, the above definitions are true for the majority of cases.
Two chemical classes of hormones
Amino acids and peptide
Steroid hormones (four-ringed chemical base) – These can cross the blood-brain barrier. They can
enter the brain.
The Endocrine Control Centre
The hypothalamus (not a ductless gland! It's a CNS structure) and pituitary. Located in the
diencephalon, just inferior to the thalamus. Controls a number of endocrine glands and a range of
physiological activities. Major point of interaction of NS and ES.
Hypothalamus is the link between the NS and ES. It is part of the CNS but it's neurons produce
hormones. Thalamus is a major relay system. By and large, all incoming sensory information goes
through the thalamus.
Corticotropin Releasing Hormone (CRH)
Synthesised in the anterior portion of the Para-ventricular nucleus (PVN) of the hypothalamus.
Stimulates secretion of Adrenocorticotropic Hormone (ACTH) from the pituitary.
Gonadotropin Releasing Hormone (GnRH)
Synthesised within the preoptic area of the hypothalamus.
Controls the release of luteinising hormone (LH) and follicle-stimulating hormone (FSH).
It is unknown whether there are one or two types of GnRH.
Growth Hormone Releasing Hormone (GH-RH)
Secreted within the ventromedial nucleus and the arcuate nucleus of the hypothalamus.
Stimulates Growth Hormone secretion from the pituitary.
Thyrotropin Releasing Hormone (TRH)
Synthesised in the PVN and anterior PVN of the hypothalamus.
Stimulates cells in the anterior pituitary gland to produce and release thyroid-stimulating hormone
(TSH).
Dopamine
Neurons located in the arcuate nucleus of the hypothalamus.
When released acts as primary prolactin-inhibitory hormone in the pituitary.
Somatostatin
Also referred to as GH-IH.
Secreted by the PVN of the HT.
Inhibits GH (as the GH-IH name would suggest) and TSH.
Also has inhibitory effects on insulin, glucagon and secretin production.
Oxytocin and Vasopressin
Synthesised in the supraoptic nuclei and in the lateral and superior PVN.
Transported to the posterior pituitary and released.
Vasopressin also referred to as antidiuretic hormone.
Both regulates water balance, blood pressure, memory.
Oxytocin: uterine contractions, parental behaviours, attachment bonds, trust. “the one social
hormone”
The Pituitary
Also called the hypophysis.
Attached to the HT by the hypophyseal stalk (infundibulum/pituitary stalk).
Anterior pituitary (adenohypophysis) – Synthesises it's own hormones.
Posterior pituitary (neurohypophysis) – Does not produce it's own hormones. Hormones produced
in the HT travel to the posterior pituitary and are released from there.
Releases six hormones, mostly tropic.
The Hormones of the PT
Adrenocorticotropic Hormone (ACTH) – Travels to the Adrenal Cortex
Growth Hormone (GH)
Prolactin (PRL) – Mammary Glands
Thyroid-Stimulating Hormone (TSH) – Thyroid Gland
Luteinising Hormone (LH) – Gonads
Follicle-Stimulating Hormone (FSH) – Gonads
Acromegaly – uncontrolled production of growth hormone (GH).
The HT-PT Relationship
Hormones of the HT stimulate secretion of hormones from the PT
It is not a one to one relationship (e.g., CRH – ACTH) nor is it unidirectional (PT hormones do
affect HT).
Neurotransmitters also regulate the pituitary not just HT.
HT is part of the limbic system. These hormones can thus be inferred to be important in
motivational and emotional control.
Pineal Gland
Superior to third ventricle and anterior to cerebellum.
Exclusively present to produce melatonin.
Directly under control of the SCN (suprachiasmatic nucleus – located in the hypothalamus).
Mostly involved with coordinating sleep/wake cycle.
Glands outside of the CNS
Thyroid/adrenal gland, pancreas, gonads and ovaries.
Thyroid Gland
Regulated by TSH, located in the neck
Produces two hormones from Iodine: Triodothryonine (T3) and Tetraiodothyronine (T4) with a
production ratio of 20:1 (T4:T3). 40% of T4 is deiodinated to T3 suggesting that T4 is just a
prehormone, which is unlikely.
T4 binds to Thyroid Binding Globulin and regulates body metabolism and controls the development
of the CNS.
Controls sexual maturation, plays a role in temperature regulation, produces parathyroid hormone
which regulates calcium. Hypo/hypersecretion associated with poor physical and mental health.
Cretinism. A failing gland is associated with increased fatigue, facial puffiness, skin discolourations,
skin dryness.