Preface | p. vii |
Contributors | p. ix |
Biological Clocks at the End of the 20th Century | p. 1 |
Clocks, Genes and Evolution: The Evolution of Circadian Organization | p. 5 |
Introduction | p. 5 |
Clocks | p. 6 |
Genes | p. 7 |
Evolution | p. 9 |
Population replication | p. 9 |
Population size | p. 10 |
The effect of novel environments | p. 10 |
Mutant and isofemale lines | p. 10 |
Ancestry, controls, and the evidence for adaptation | p. 11 |
Tradeoffs and the genetic architecture of fitness | p. 12 |
Evidence for adaptive significance of circadian organization | p. 13 |
Persistence circadian rhythms in aperiodic environments | p. 13 |
Circadian resonance and fitness effects of rhythm disruption | p. 14 |
Significance of biological clocks in the wild | p. 15 |
Evidence from clines | p. 15 |
Selection studies | p. 15 |
What do we know about the evolutionary genetics of circadian organization? | p. 17 |
Future Paths | p. 18 |
References | p. 20 |
Circadian Frequency and Its Variability | p. 24 |
Functional aspects of [tau] | p. 24 |
Is the deviation of [tau] from 24 hours adaptive? | p. 25 |
Can variations of [tau] tell us something about mechanism? | p. 28 |
Precision | p. 29 |
Stability | p. 29 |
Accuracy | p. 29 |
Model simulations | p. 33 |
Conclusion | p. 35 |
References | p. 35 |
Period Doubling of Rhythmic Water Regulation in Plants | p. 38 |
Introduction | p. 38 |
Models of the water regulatory system | p. 39 |
A mathematical description | p. 41 |
Atypical waveforms | p. 41 |
Discussion of the model and period doubling | p. 43 |
References | p. 44 |
The Genetics and Molecular Biology of Circadian Clocks | p. 46 |
Introduction | p. 46 |
The circadian clock in bacteria | p. 46 |
The circadian clock in fungi | p. 48 |
The circadian clock in insects | p. 50 |
The circadian clock in vertebrates | p. 53 |
Conclusion | p. 56 |
References | p. 56 |
The Circadian Systems of Cells | p. 60 |
Introduction | p. 60 |
Gonyaulax, an example for a single cell clock | p. 61 |
Entrainment of cellular clocks | p. 63 |
Coupling between oscillators | p. 64 |
Open questions | p. 66 |
References | p. 66 |
Retinal Circadian Rhythms | p. 71 |
Introduction | p. 71 |
Mechanisms controlling the sensitivity of compound eyes are governed by the circadian clock | p. 73 |
The circadian pacemaker controlling these retinal rhythms lies in the photic input pathways next to the higher optic neuropils | p. 73 |
Efferent fibres signal the circadian time to the retina | p. 76 |
Retinal rhythms directly monitor the circadian "System Time" | p. 79 |
Conclusion | p. 80 |
References | p. 80 |
Perception of Natural Zeitgeber Signals | p. 83 |
Introduction | p. 83 |
Dawn and dusk deliver the most precise natural timing cues | p. 83 |
Simulated twilight results in better synchronisation than lights on/off | p. 84 |
Specialised photoreceptors and/or neuronal networks are necessary as zeitgeber receptors | p. 85 |
The photoreceptor system of scorpions as a model of a dusk detector | p. 88 |
Eyes of the biological clocks in vertebrates and invertebrates | p. 90 |
Conclusions | p. 90 |
References | p. 91 |
Photoreceptors for the Circadian Clock of the Fruitfly | p. 94 |
Introduction | p. 94 |
Characteristics of circadian rhythms in Drosophila | p. 95 |
Action spectra suggest the involvement of several photopigments in circadian photoreception | p. 95 |
Generation of circadian rhythmicity on the molecular level | p. 100 |
Entrainment of the molecular feed back oscillator | p. 101 |
Conclusions | p. 103 |
References | p. 104 |
Photoentrainment of Vertebrate Circadian Rhythms | p. 107 |
Introduction | p. 107 |
Photoentrainment in non-mammals | p. 108 |
Extraretinal photoreceptors | p. 108 |
The characterisation of the extraretinal photoreceptors | p. 109 |
Novel extraretinal photopigments | p. 110 |
Multiple extraretinal photopigments | p. 111 |
Photoentrainment in mammals | p. 111 |
Novel ocular photoreceptors | p. 112 |
A novel opsin photopigment in the mammalian retina | p. 113 |
A role for rods and cones | p. 114 |
Multiple photopigments and twilight detection | p. 114 |
References | p. 116 |
Circadian Organization in Fish and Amphibians | p. 120 |
Physiology of fish circadian systems | p. 120 |
Molecular biology of teleost circadian systems | p. 123 |
Physiology of amphibian circadian systems | p. 124 |
Molecular biology of amphibian circadian systems | p. 125 |
References | p. 126 |
The Circadian Organization of Reptiles | p. 129 |
Introduction | p. 129 |
Pineal complex in the regulation of circadian rhythms | p. 130 |
Circadian oscillation in vitro | p. 130 |
Role of pineal and melatonin in regulation of circadian rhythms | p. 132 |
Pineal and seasonality | p. 133 |
Role of the retina in the circadian system | p. 136 |
Role of hypothalamic areas in circadian organization | p. 137 |
Conclusions | p. 140 |
References | p. 140 |
The Circadian Pacemaking System of Birds | p. 144 |
Introduction | p. 144 |
General organization of the avian circadian pacemaking system | p. 145 |
The pineal gland | p. 145 |
The retina | p. 147 |
The avian "SCN" | p. 148 |
Functional significance of the individual circadian systems for the generation of circadian rhythms at the organismic level | p. 148 |
Plasticity and seasonality of the circadian pacemaking system | p. 154 |
The transduction of information about time into complex behaviour | p. 154 |
Possible implications for ecology and behaviour | p. 156 |
Conclusions, speculations and perspectives | p. 158 |
References | p. 159 |
Neurochemical Aspects of the Entrainment of the Mammalian Suprachiasmatic Circadian Pacemaker | p. 164 |
Introduction | p. 164 |
Other RHT neurotransmitters | p. 166 |
Substance P | p. 166 |
Pituitary adenylate cyclase activating polypeptide | p. 168 |
Non-photic inputs to the SCN | p. 169 |
Serotonin | p. 169 |
Neuropeptide Y | p. 170 |
GABA | p. 171 |
Nitric oxide | p. 172 |
Acetylcholine | p. 172 |
Intrinsic neuropeptides of the SCN | p. 173 |
Gastrin-releasing peptide | p. 173 |
Vasoactive intestinal polypeptide | p. 174 |
Arginine vasopressin | p. 175 |
Somatostatin | p. 175 |
Other neural inputs | p. 175 |
Neurotensin | p. 175 |
Orexin/Hypocretin | p. 176 |
Growth hormone-releasing factor | p. 176 |
Corticotropin-releasing factor | p. 177 |
Future studies | p. 177 |
References | p. 178 |
Photoperiodism in Plants | p. 181 |
Introduction | p. 181 |
The discovery of photoperiodism | p. 181 |
Selective advantage | p. 183 |
Perception and induction occurs in the leaves | p. 183 |
Induction requires measurement of day or night length | p. 183 |
Control of the photoperiodic response rhythm (PRR) | p. 185 |
Actions of light; roles of photoreceptors | p. 188 |
Conclusions | p. 189 |
References | p. 190 |
Photoperiodism in Birds and Mammals | p. 192 |
Photoperiodic regulation of seasonal reproduction | p. 192 |
The role of the circadian clock in photoperiodic time measurement | p. 193 |
Basic principles | p. 193 |
Birds | p. 194 |
Photoperiodism in mammals: recent developments | p. 198 |
The neuroendocrine mechanisms regulating reproduction in birds | p. 199 |
Photostimulation | p. 199 |
The role of gonadotrophin releasing hormone (GnRH) in the photoperiodic control of reproduction | p. 199 |
Photorefractoriness | p. 201 |
The role of melatonin in seasonal neuroplasticity in songbirds: its action as an inhibitory hormone | p. 201 |
References | p. 203 |
Ultradian Rhythms | p. 207 |
Introduction | p. 207 |
Mechanisms | p. 208 |
Basic rest-activity cycle | p. 208 |
Allometry | p. 209 |
Functions | p. 210 |
Rhythms in voles | p. 212 |
References | p. 213 |
Biological Rhythms in Arctic Animals | p. 216 |
Introduction | p. 216 |
Activity rhythms in the Arctic | p. 217 |
Pineal secretion of melatonin | p. 219 |
Adaptations to Arctic light conditions | p. 220 |
References | p. 222 |
Diversity in the Circadian Response to Melatonin in Mammals | p. 224 |
Introduction | p. 224 |
Entrainment to melatonin | p. 224 |
Melatonin administration under LD entrainment | p. 227 |
Melatonin phase response curves | p. 228 |
Site(s) of melatonin action | p. 228 |
Conclusions | p. 229 |
References | p. 229 |
Light Sensitivity of the Biological Clock | p. 232 |
Introduction | p. 232 |
The photoperiodic clock | p. 233 |
CRPP: phasic effects | p. 235 |
Induction vs. entrainment | p. 236 |
Temporal photosensitivity | p. 236 |
Non-reproductive circadian functions | p. 237 |
Non-circadian functions | p. 238 |
Remarks | p. 238 |
Conclusions and implications | p. 239 |
References | p. 240 |
Index | p. 245 |
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