Biological RhythmsPowerPoint PresentationBiological RhythmsSlide 4Jet Lag what cause it?Circadian RhythmsSlide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15SAD (Seasonal Affective Disorder)Biological RhythmsBehavioral NeuroscienceNu-Chu Liang, [email protected] Bldg 725217-244-7873Office H: Mon, 11:00 – 12:00 AMObjective•to learn neural basis of biological rhythms, sleep, chemical senses and feeding•to learn to apply knowledge to daily life•How to do well?–Attend class and take notes–Read the reading assignments–Ask questions and join discussion in classBiological Rhythms•Circannual–yearly, migratory cycle•Infradian–> a day, menstrual cycle•Circadian–daily, human sleep-wake cycle•Ultradian–< a day, meals, sleep cyclesBiological Rhythms•Zeitgeber: cues that synchronize biological rhythms•Entrainment: the process of synchronizing a biological rhythm to an environmental stimulusKolb & Whishaw, An Introduction to Brain and Behavior, Fourth EditionJet Lagwhat cause it?http://www.stepandswing.net/Circadian Rhythms•Free running rhythms•Human free running period is > 24 hrs.Copyright © 2014 Pearson Education, Inc. John Pinel, BiopsychologyNathaniel Kleitman monitors sleep of assistant, Bruce Richardson, during sleep and wakefulness experiment in Mammoth Cave, Kentucky, 1938.Circadian RhythmsKolb & Whishaw, An Introduction to Brain and Behavior, Fourth Edition constant light vs. constant dark•Circadian rhythm of blind•Photic information for SCN is neither rods nor cones–why rod & cone blind show normal circadian rhythm?•Melanopsin–in ganglion cells in the retina–pupillary response to lightCopyright © 2014 Pearson Education, Inc. Neil Carlson, Physiology of BehaviorThe Retinohypothalamic TractKolb & Whishaw, An Introduction to Brain and Behavior, Fourth Edition Neural MechanismsThe Retinohypothalamic TractBiological Psychology, Fifth EditionNeural MechanismsCopyright © 2014 Pearson Education, Inc. Neil Carlson, Physiology of BehaviorSuprachiasmatic Nucleus (SCN):master oscillator of biological rhythmsKolb & Whishaw, An Introduction to Brain and Behavior, Fourth Edition•Intrinsic rhythm in the SCN–more active during the light period–isolated SCN neurons retain a periodic rhythmCopyright © 2014 Pearson Education, Inc. Neil Carlson, Physiology of BehaviorNeural MechanismsLightDarkFiring Rate of Individual SCN Neurons in a Tissue CultureCopyright © 2014 Pearson Education, Inc. Neil Carlson, Physiology of Behavior•Specific genes and transcription factors are responsible for the firing rhythms (intrinsic clock) in the SCN cells•Clock genes are also found in cells of other organ•SCN pacemaker drives a number of “slave oscillators,” each of which controls the rhythmic occurrence of one behavior (e.g., body temperature)SCN•SCN implant–SCN cell activity is geneticallly programmed–Lesions of the SCN lead to arrhythmic animal–transplants of embryonic SCN cells restore the rhythm Kolb & Whishaw, An Introduction to Brain and Behavior, Fourth Edition•Controlled by day length•Pineal gland–seasonal rhythms–secretes melatonin–SCN fetal transplant does not restore circannual rhythmCircannual RhythmCopyright © 2014 Pearson Education, Inc. John Pinel, Biopsychology•SCN is involved in circannual rhythm-male hamster testosterone secretion-breeding season•SCN – paraventricular nucleus of the hypothalamus (PVN) – sympathetic nervous system – pineal glandCircannual RhythmKolb & Whishaw, An Introduction to Brain and Behavior, Fourth EditionSAD (Seasonal Affective Disorder)•Winter SAD-seasonal experience of sadness-interpersonal difficulties-decreased activity-increased sleep time-carbohydrate craving-increased appetite-weight gain-respond to bright light