CAB- behavioural pharmacology

• Behavioural Pharmacology


  Central nervous system (CNS), Endocrine system, Neurotransmitters, Drug classes and their application on behaviour modification
• Communication in the body


  • The Nervous System (Central nervous system, Peripheral nervous system), The Endocrine System
• Peripheral nervous system


  • Consists of nerves that extend throughout the body, Nerves are axons bundled together, Motor nerves transmit information from the CNS to muscles, organs and glands, Sensory nerves in the sensory surfaces convey information to the CNS
• Autonomic Nervous System (ANS)


  • Sympathetic (Flight or fight response), Parasympathetic (Recuperative function), There are two branches of the ANS
• Nervous tissue


  • Specialised cells that conduct electrical impulses, Dendrites, Cell body, Axon
• Nervous stimuli


  • Chemicals for taste, smell and maintenance of homeostasis, Temperature for thermoregulation, Light for vision, Vibration for hearing, Pressure for touch
• CNS


  • Brain and spinal cord, Bone protection, Continuous at foramen magnum, Connective membranes, Meninges
• Myelin sheath


  Fatty insulating substance that increases the speed of transmission of signals
• Synapses


  • Synapse is a contact point between neurons or between neuron and surrounding cells, Presynaptic membrane, Postsynaptic membrane, Synaptic cleft
• The Synapse - CNS


  Axon of pre-synaptic cell to dendrites of post-synaptic cell, Drug or hormone administered to an animal may affect the way 'messages' travel across the synaptic cleft
• Synapases


  Presynaptic axon terminals contain many synaptic vesicles, Each vesicle contains a neurotransmitter, Vesicles fuse with presynaptic membrane, Releasing the neurotransmitter into the synaptic cleft, Neurotransmitter diffuses across the cleft, Receptors in postsynaptic membrane capture and react to neurotransmitters, Causes changes in electrical activity of postsynaptic cell
• Neurotransmitters


  • Dopamine, Noradrenaline, Serotonin, Gamma-aminobutyric acid (GABA)
• Response to a threat


  • Behaviour changes, Increased alertness, Fight, flight or freeze response, Increased frequency / intensity of vocalisations, Reduced maintenance behaviour, Increased aggression, Behavioural withdrawal, inattentiveness, apathy, Hyper / hypophagia (change in food intake/eating), Polydipsia (excessive thirst/drinking), Abnormal behaviours, Teaching an animal in a fearful state (past threshold) is very difficult as they are preoccupied with these other behaviours
• Physiological changes


  • Glucocorticoids, Endogenous opioids, Adrenaline & noradrenaline, Immune function, Heart rate & BP, Blood supply to tissues increases, Blood vessels in gut wall constrict, and blood is diverted away, slowing digestion
• Stress influences the balance between the sympathetic and parasympathetic systems


  Depending on the situation, the type of stressor and the individual, the relative activity of either, the sympathetic nervous system will be increased
• Physiological indicators of wellbeing and stress


  Can indicate a disruption to the body's homeostatic mechanisms
• How does the SNS have this effect on the body?

  Direct Action: Neurons of SNS innervate smooth muscle and heart muscle, Indirect Action: Neurons of SNS innervate the adrenal glands, SAM & HPA: The SNS has two modes of action
• Physiological changes are controlled by the nervous and endocrine systems


  • The autonomic (sympathetic and parasympathetic) nervous system and the hypothalamic–pituitary–adrenal (HPA) endocrine axis mediate many of the physiological responses to stress
• Indirect Action 1. SAM axis


  SNS activity causes the release of catecholamines from the adrenal medulla, Catecholamines released into the blood and travel around the body affecting any organs which have appropriate receptors
• Indirect Action 2. HPA axis


  Hypothalamus / pituitary gland / adrenal cortex, Release of Glucocorticoids from the Adrenal Cortex, Type of glucocorticoid depend on the species
• Role of pharmacology on behavioural medicine


  Drug therapy correctly and carefully used is useful adjunct to behaviour modification, In some cases behaviour modification may be unsuccessful without it, However, drug therapy alone is usually not enough to alter an animal's behaviour in the long term
• Neurotransmission


  Can increase or decrease to respond to or generate physiologic functions / needs, Many neurological or psychiatric diseases caused by pathologic over-activity or under-activity of neurotransmission, Pharmacological interventions can be helpful in some cases
• Neurotransmitter Breakdown


  Re-uptake by the presynaptic cell, Enzyme deactivation in the synaptic cleft, Mode of drug action
• Classes of psychotropic drugs in behavioural medicine


  • Antipsychotics, Anxiolytics, Anti depressants, Anti-convulsants, Hormones, Pheromones
• Effects of psychoactive drugs


  Commonly used to aid: The reduction of anxiety, To manage physiological states that may affect behaviour, To decrease general levels of arousal, To manage compulsive disorders
• Antipsychotics


  Now rarely used in veterinary behavioural medicine, Previously used in reducing an animal's ability to attend to what is happening in its environment
• Anxiolytics


  Used to reduce an animal's general level of anxiety, Some drugs in this class have a sedative effect and reduce an animal's capacity to learn
• Anti depressants


  Anxiety reducing properties, Often not licensed for animal use
• Anti-convulsants


  Most frequent use in animal behaviour is for compulsive disorders like Light /shadow chasing, Tail chasing, Spinning, Acral lick dermatitis, Flank sucking
• Hormones


  Synthetic version of hormones commonly used to regulate some sexually dimorphic behaviour, Can also be used for e.g. inter dog aggression, Tardac - older product might have uses, Suprelorin - under the skin, lasts for 6 months
• Pheromones


  Synthetic versions of naturally produced dog or cat pheromones, For use in the management of underlying anxiety, Adaptil (was DAP), Feliway
• Drugs licensed for use in UK


  Progestogens - 1st drugs licensed for use in behaviour therapy, Oppose hormonal effects, Calming, Tricyclic Antidepressants - Broad function is to raise thresholds for different behaviours, Monoamine Oxidase Inhibitors - Broad effects, but particularly vs. dopamine
• Authorised behaviour VMPs


  • Clomicalm - Clomipramine hydrochloride, Reconcile - Fluoxetine, Selgian - Selegiline hydrochloride, Sileo - Dexmedetomidine hydrochloride, Pexion - Imepitoin
• Veterinary prescribing cascade


  Only vet surgeons may legally diagnose, prescribe, advise on the basis of diagnosis and perform surgery on animals, The Veterinary Surgeons (Exemptions) Order 1962 allows for some treatments to be provided by other people
• Complementary therapies


  • Acupuncture – qualified and trained vet only, Homeopathy – qualified vet only but ready-made remedies are available, TTouch – manipulative therapy, Hydrotherapy – manipulative therapy