The auditory cortex of the bat Phyllostomus discolor [Elektronische Ressource] : functional organization and processing of complex stimuli / vorgelegt von Susanne Hoffmann

Susanne Hoffmann

Sujets

• Biologie

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2009
• Nombre de lectures: 30
• Langue: English
• Poids de l'ouvrage: 10 Mo

Extrait

The auditory cortex of the bat Phyllostomus
discolor: Functional organization and
processing of complex stimuli.






Dissertation
der Fakultät für Biologie
der Ludwig- Maximilians Universität
München


Vorgelegt von
Susanne Hoffmann

am 02. März 2009























































1. Gutachter: Prof. Dr. Gerd Schuller
2. Gutachter: PD Dr. Lutz Wiegrebe
Tag der mündlichen Prüfung: 23.06.2009




Contents

ZUSAMMENFASSUNG___________________________________________________________ V
SUMMARY ___________________________________________________________________ VII
GENERAL INTRODUCTION _____________________________________________________ 1
1. PSYCHOPHYSICAL AND NEUROPHYSIOLOGICAL HEARING THRESHOLDS IN
THE BAT PHYLLOSTOMUS DISCOLOR ____________________________________________ 5
1.1 ABSTRACT __________________________________________________________________ 5
1.2 INTRODUCTION ______________________________________________________________ 6
1.3 METHODS 7
1.3.1 PSYCHOPHYSICS ____________________________________________________________ 7
1.3.1.1 Experimental animals_______________________________________________________ 7
1.3.1.2 Experimental setup_________________________________________________________ 7
1.3.1.3 Acoustic stimuli ___________________________________________________________ 8
1.3.1.4 Training procedure 8
1.3.2 NEUROPHYSIOLOGY 9
1.3.2.1 Surgery__________________________________________________________________ 9
1.3.2.2 Recording procedure ______________________________________________________ 10
1.3.2.3 Data analysis ____________________________________________________________ 10
1.4 RESULTS 11
1.4.1 PSYCHOPHYSICS 11
1.4.2 NEUROPHYSIOLOGY ________________________________________________________ 12
1.5 DISCUSSION ________________________________________________________________ 14
1.5.1 COMPARISON WITH NEUROPHYSIOLOGICAL DATA OF OTHER PHYLLOSTOMID BATS _______ 16
1.5.2 COMPARISON WITH BEHAVIORAL AUDIOGRAMS OF OTHER PHYLLOSTOMID BATS ________ 17
1.6 ACKNOWLEDGEMENTS_______________________________________________________ 19
2. THE AUDITORY CORTEX OF THE BAT PHYLLOSTOMUS DISCOLOR:
LOCALIZATION AND ORGANIZATION OF BASIC RESPONSE PROPERTIES _______ 21
2.1 ABSTRACT___________________________________________________________________ 21
2.1.1 BACKGROUND_______________________________________________________________ 21
2.1.2 RESULTS 21
I2.1.3 CONCLUSIONS_______________________________________________________________ 22
2.2 BACKGROUND________________________________________________________________ 22
2.3 RESULTS ____________________________________________________________________ 23
2.3.1 AUDITORY RESPONSES IN THE CORTEX OF PHYLLOSTOMUS DISCOLOR____________________ 23
2.3.2 NEUROANATOMY ____________________________________________________________ 25
2.3.3 BASIC NEURONAL RESPONSE PROPERTIES _________________________________________ 29
2.3.4 REPRESENTATION OF NEURONAL RESPONSE PROPERTIES IN CORTICAL FIELDS_____________ 32
2.4 DISCUSSION__________________________________________________________________ 36
2.4.1 COMPARISON WITH THE AUDITORY CORTEX OF OTHER BATS __________________________ 36
2.4.2 INFLUENCE OF ANESTHESIA AND MULTI UNIT RECORDINGS ON RESPONSE PATTERNS________ 37
2.4.3 PARCELLATION OF THE AUDITORY CORTEX IN P. DISCOLOR ___________________________ 38
2.5 CONCLUSIONS________________________________________________________________ 40
2.6 METHODS ___________________________________________________________________ 41
2.6.1 EXPERIMENTAL ANIMALS______________________________________________________ 41
2.6.2 ANESTHESIA AND SURGICAL PREPARATION ________________________________________ 41
2.6.3 STEREOTAXIC PROCEDURE AND VERIFICATION OF RECORDING SITES AND CORRELATION WITH
NEUROARCHITECTURAL FEATURES ___________________________________________________ 41
2.6.4 ACOUSTIC STIMULI AND RECORDING OF NEURONAL RESPONSES________________________ 42
2.6.5 DATA ANALYSIS _____________________________________________________________ 44
2.7 ACKNOWLEDGEMENTS ________________________________________________________ 45
3. A NEURAL CORRELATE OF STOCHASTIC ECHO IMAGING __________________ 47
3.1 ABSTRACT___________________________________________________________________ 47
3.2 INTRODUCTION_______________________________________________________________ 47
3.3 MATERIALS AND METHODS _____________________________________________________ 48
3.3.1 ANIMALS 48
3.3.2 PSYCHOPHYSICS _____________________________________________________________ 49
3.3.3 NEUROPHYSIOLOGY __________________________________________________________ 50
3.4 RESULTS ____________________________________________________________________ 51
3.4.1 PSYCHOPHYSICS 51
3.4.2 NEUROPHYSIOLOGY 52
3.4.3 COMPARISON OF PSYCHOPHYSICS AND NEUROPHYSIOLOGY ___________________________ 56
3.5 DISCUSSION__________________________________________________________________ 57
3.6 ACKNOWLEDGEMENTS ________________________________________________________ 61
4. AN AREA SENSITIVE TO APPARENT ACOUSTIC MOTION IN THE AUDITORY
CORTEX OF THE BAT PHYLLOSTOMUS DISCOLOR_______________________________ 63
4.1 ABSTRACT___________________________________________________________________ 63
4.2 INTRODUCTION_______________________________________________________________ 64
4.3 METHODS 65
4.3.1 EXPERIMENTAL ANIMALS AND SURGICAL PREPARATION______________________________ 65
4.3.2 STEREOTAXIC PROCEDURE AND VERIFICATION OF RECORDING SITES ____________________ 65
II 4.3.3 ACOUSTIC STIMULATION USED FOR DETERMINATION OF BASIC NEURONAL RESPONSE PROPERTIES
_______________________________________________________________________________ 66
4.3.4 TWO-TONE STIMULI (APPARENT HORIZONTAL ACOUSTIC MOTION)______________________ 66
4.3.5 RECORDING OF NEURAL RESPONSES______________________________________________ 69
4.3.6 DATA ANALYSIS _____________________________________________________________ 70
4.3.6.1 Basic response properties ____________________________________________________ 70
4.3.6.2 Response properties to dynamic two-tone stimulation ______________________________ 70
4.4 RESULTS ____________________________________________________________________ 73
4.4.1 MOTION INSENSITIVE UNITS 74
4.4.2 MOTION SENSITIVE UNITS______________________________________________________ 77
4.4.3 REPRESENTATION OF MOTION SENSITIVITY AT THE CORTICAL SURFACE__________________ 82
4.4.4 BASIC RESPONSE PROPERTIES OF MOTION SENSITIVE AND INSENSITIVE UNITS IN THE PDF ___ 84
4.4.5 MOTION SPECIFIC RESPONSE PROPERTIES OF MOTION SENSITIVE AND INSENSITIVE UNITS IN THE
PDF ___________________________________________________________________________ 84
4.5 DISCUSSION__________________________________________________________________ 86
4.5.1 COMPARISON TO OTHER STUDIES ________________________________________________ 86
4.5.2 MOTION SENSITIVITY _________________________________________________________ 87
4.5.3 INHIBITION BY DYNAMIC STIMULATION ___________________________________________ 89
4.6 ACKNOWLEDGEMENTS ________________________________________________________ 90
GENERAL DISCUSSION 91
THE PARCELLATION OF THE PHYLLOSTOMUS AC IN COMPARISON TO OTHER BATS__________ 93
FUNCTIONAL ROLE OF DIFFERENT AUDITORY CORTICAL SUBFIELDS IN BATS _______________ 94
OUTLOOK ____________________________________________________________________ 97
REFERENCES _________________________________________________________________ 99
LIST OF ABBREVIATIONS_____________________________________________________ 113
LIST OF FIGURES ____________________________________________________________ 115
LEBENSLAUF ________________________________________________________________ 117
DANKSAGUNG _______________________________________________________________ 119
EHRENWÖRTLICHE ERKLÄRUNG ____________________________________________ 121

IIIIV




Zusammenfassung

Als auditorischer Kortex wird der Teil des Neokortex bezeichnet, der Neurone enthält, die auf
akustische Reize antworten. Er stellt die höchste Ebene der Verarbeitung akustischer
Information in der aufsteigenden Hörbahn dar. Die in dieser Arbeit zusammengefassten
Studien untersuchten den auditorischen Kortex der Fledermaus Phyllostomus discolor mit
Hilfe einfacher sowie komplexer akustischer Reize. Innerhalb der Experimente wurden
unterschiedliche Methoden verwendet (z.B. Psychophysik und Neuroanatomie). Der
Schwerpunkt der Arbeit liegt jedoch auf der elektrophysiologischen Untersuchung des
auditorischen Kortex.
Das erste Kapitel beschäftigt sich mit einer Studie, die den Hörbereich von P. discolor anhand
neuronaler Hörschwellen und Verhaltenshörschwellen untersuchte. Die Ergebnisse dieser
Studie zeigen, dass akustische Reize mit ein