Neural Basis of Elementary Behavior in Stick Insects

1 Introduction.- 1.1 Statement of the Problem.- 1.2 The Experimental Animal and Its Behavior.- 1.3 Experimental Strategy.- 2 Behavioral Components of Twig Mimesis - Experiments on the Femur-Tibia Joint.- 2.1 Twig Mimesis and Its Components.- 2.2 Control of the State of Activity.- 2.3 Thanatosis.- 2.4 Catalepsy (Flexibilitas Cerea).- 2.4.1 Description and Definition of Catalepsy.- 2.4.2 Catalepsy in the Femur-Tibia Joint as a Characteristic of a Feedback Control Loop.- 2.5 Rocking.- 2.5.1 Description of Rocking.- 2.5.2 Possible Origins of Rocking Movements.- 2.5.3 Frequency Response of the Open Femur-Tibia Control Loop.- 2.5.4 Rocking After Ablation of Sense Organs - Definition of Central Oscillator and Program.- 2.5.5 Further Support for a Central Oscillator.- 2.6 The Femur-Tibia Control Loop.- 2.6.1 Force Measurements on the Extensor and Flexor Muscles of the Tibia.- 2.6.2 Simulation of the Control System Based on the Results of Muscle Force Measurements.- 2.6.3 Gain Control.- 2.6.4 Influence of Other Sense Organs on the Input-Output Relationships of the Control Loop.- 2.7 Evolution of Catalepsy and Rocking.- 2.7.1 The Femur-Tibia Control Loop in Schistocerca.- 2.7.2 Femur-Tibia Control Loop, Catalepsy and Rocking in Extatosoma tiaratum and Cuniculina impigra.- 2.7.3 Hypotheses on the Evolution of Catalepsy and Rocking.- 2.8 Neural Basis of the Femur-Tibia Control Loop.- 2.8.1 The Motor Neurons of the Extensor Tibiae Muscle.- 2.8.2 The Responses of FETi and SETi to Stimulation of the Femoral Chordotonal Organ.- 2.8.3 Alterations of the FETi and SETi Membrane Potential in Cuniculina.- 2.8.4 Neuronal Equivalents of the Elements of Control-Loop Simulation.- 2.9 Significance of Systems Theory (Cybernetic) Methods for the Strategy Used Here.- 2.10 Arousal.- 3 Other Behaviors of the Stationary Animal.- 3.1 Claw Flexing.- 3.2 Active Movements of the Femur-Tibia Joint in Restrained Animals.- 3.2.1 Quantitative Description of the Movement.- 3.2.2 Stimulation of the Chordotonal Organ in the Active Animal.- 3.2.3 Reflex Reversal, Program-Dependent Reaction.- 3.3 Control of the Coxa-Trochanter Joint.- 3.4 Control of the Subcoxal Joint.- 3.4.1 Description of the Response.- 3.4.2 The Motor Neurons of the Retractor Coxae Muscle.- 3.4.3 Response of the Retractor Coxae Motor Neurons to Movement of the Joint.- 3.5 Leg Raising by the Standing Animal.- 3.6 Height Control by a Standing Animal.- 4 Walking.- 4.1 Introduction.- 4.2 Control of a Single Leg.- 4.2.1 Description of the Walking Movement of a Single Leg.- 4.2.1.1 Free-Moving Animals.- 4.2.1.2 Adults Walking on a Treadwheel.- 4.2.1.3 Animals on a Mercury Substrate.- 4.2.2 Description of the Torques in Single Leg Joints During Stance Phase.- 4.2.3 Motor Neuron Activity During a Normal Step.- 4.2.4 Afferent Influences on the Walking Movement of a Single Leg.- 4.2.4.1 Femoral Chordotonal Organ.- 4.2.4.2 Campaniform Sensilla on the Trochanter.- 4.2.4.3 Position Receptors on the Subcoxal Joint.- 4.2.5 Motor Output During Prolongation of a Phase.- 4.2.5.1 Remaining in Stance Phase.- 4.2.5.2 Remaining in Swing Phase (Saluting).- 4.2.5.3 Conclusions.- 4.2.6 Structure and Localization of the Walking Program.- 4.2.6.1 Ablation of the Periphery.- 4.2.6.2 Unspecific Stimulation of Sense Organs.- 4.2.6.3 Stimulation of Single Receptor Organs.- 4.2.6.4 Elimination of Higher Centers.- 4.2.6.5 Conclusions.- 4.2.7 Responses to Irregularities of the Walking Surface.- 4.2.7.1 Control of Femur-Tibia Joint Position During Walking.- 4.2.7.2 Load Increase.- 4.2.7.3 Obstacles During the Swing Phase.- 4.2.7.4 Control of Segment Height.- 4.2.8 Model for the Control of a Single Leg.- 4.3 Interactions Between Legs that Do Not.- Influence Timing.- 4.3.1 Hindleg "Aims" at Tarsus of Middle Leg.- 4.3.2 Treading-on-Tarsus (TOT) Reflex.- 4.3.3 Increased Loading.- 4.3.4 Influence of Searching Movements on the Other Legs.- 4.3.5 Control of Body Height During Walking.- 4.3.6 Amputation of Single Legs.- 4.4 Coordination.- 4.4.1 Description of Leg Coordination - Gaits.- 4.4.1.1 Nymph Walking.- 4.4.1.2 Free Walking Adults.- 4.4.1.3 Adult Walking on a Treadwheel.- 4.4.1.4 Walking on a Mercury Surface.- 4.4.1.5 Dependence of Coordination on the Resistance.- 4.4.2 Coordination After Surgical Intervention.- 4.4.3 Coordination Models.- 4.5 Walking Backwards.- 5 Orientation.- 5.1 Gravity Orientation.- 5.1.1 Description of Behavior.- 5.1.2 Receptors Involved in Behavior.- 5.1.3 Processing of Proprioceptive Input.- 5.2 Light Orientation.- 5.2.1 The Carausius Eye.- 5.2.2 Photomenotaxis.- 5.2.3 Optomotor Response - Color Vision.- 5.2.4 Orientation to Visual Patterns.- 5.3 Idiothetic Orientation.- 6 Anatomy of the Muscles, Nerves, and Sense Organs of the Carausius Thorax.- 6.1 Anatomy of the Thorax and the Legs.- 6.1.1 Skeletal Components and Joints.- 6.1.2 Musculature.- 6.1.3 Nervous System.- 6.2 Anatomy and Physiology of the Sense Organs of the Legs.- 6.2.1 Coxa.- 6.2.2 Trochanter.- 6.2.3 Femur.- 6.2.4 Tibia.- 6.2.5 Tarsus.- 6.3 Motor Innervation of the Leg Muscles.- 6.3.1 Retractor Coxae.- 6.3.2 Depressor Trochanteris.- 6.3.3 Extensor Tibiae.- 6.3.4 Flexor Tibiae.- 6.3.5 Retractor Unguis.- References.