05 Basic Plan and Development

• neurons highly conserved, connection changes

  • myelin invented by vertebrates

  • unipolar neurons in invertebrates

  • tendency towards centralization

  -> place of more sensory input -> more nerves

  • octopus brain in arm (can be moved individually), central coordination head

• still free to differentiate for function

  • motor/sensory, projection/local, switch, pacemaker

    
    

blastula -> neural induction -> gastrulation -> neurolation

• neuroectodermal tissue differentiate from ectoderm -> neural plate + neural plate border

• neural plate folds -> neural plate borders join (-> neural crest cells for PNS/spinalganglia)

• neural tube closes -> separating from ectoderm

• notochord medial hinge point, degenerates after

• invertebrates

• ectoderm transplanted in recipient for development of second neural plan

• Spemann organizer

• ectoderm differentiation

• Noggin, Chordin, Follistatin inhibit BMP

  • BMP: TF for ectoderm into epidermis

• Prosencephalon -> Telencephalon (Cortex, Basal Ganglia) + Diencephalon (Thalamus, Hypothalamus)

• Mesencephalon -> Mesencephalon (Culliculi, Substantia nigra)

• Rhombenceohalon -> Metencephalon (Pons, Cerebellum) + Myelencephalon (Medulla obl)

• homebox genes

• highly conserved

• dermatomes

• more classes of genes for forebrain, midbrain and hindbrain border

• gradients

• shh

• Wnt1

• Fgf8

• Dopamine (subst nigra)

• OTX2

• PAX6

• SIX3

• GBX2

• PAX2

• mid/hindbrain petterning

  • mesencephalon and r1

• somas close to CSF, connection outside

  • frob brain similar

• cordas dorsalis produces shh

• autonome body functions: digestion, breathing, heart beat, blood pressure

• transmission of general attention and arousal level to spinal cord

• sensomotorische Integration of head/neck area

  • mimic, tongue movement, ear movement, skin sensitivity, taste, gleichgewicht, schallwahrn

  
  

• frequency and depth of breathing

  • pontine respiratory group +/- -> dorsal and ventral respiratory group -> accesroy respiratory muscles and external intercotal muscle + diaphragm

• inputs from

  • blood chemoR

  • N. X and N. IX

  • cortex and hypothalamus

• discrepancies of intended and actual movement

• motoric learning

• control of automatic movements

• fine motor control + strength

• time structures

• pons: information from cortex to cerebellum

• 3 layers: molecular, Purkinje, granulate layer

• climbing fibers, mossy fibers, stellate cells, basket cells, golgi cells, parallel cells

• v.a. Colliculi lamina quadrigemina

  • c. inf: Hörbahn

  • c. sup: Sehbahn

• Steuerung akustisch und visuell ausgelöster Reize

• sensomotorische Integration zur reflexiven Bewegungskontrolle

• Augenbewegung (Sakkaden)

• Kopfbewegungen

• Kontrolle Aktivitätsniveau Vorderhirn

  
  

• Thalamus: Vorverarbeitung der zum Vorderhirn aufsteigenden sensorischen Informationen

• WW mit Vorderhirn: Weckfunktion, Bahnung von Informationen

• Hypothalamus: Steuerung autonomer, endokriner, visceraler Fkt.

• Basalganglien

  • Striatum (Ncl caudatus und Putamen), glob pallidus, subst nigra

  • willkürliche motor Bewegungen, prozeduales Lernen, -Motivation, Belohnung, Handlungsselektion, Regulation der motorischen und prämotorischen kortikalen Areale

  • Dysfkt: Parkinson, Tourette, Huntington, Schizophrenie

    
    

• graue +weiße Substanz

• Gedächtnis, Aufmerksamkeit, Wahrnung, Kognition, Bewusstsein, Denken, Sprache

• no corda dorsalis under forebrain

• frontal pole: ANR acts as organization centre

• no motor neurons in forebrain

• dorsoventral axis of forebrain

  • dorsal pallial region: Neocortex, Archicortex (hoippocampus) - sheet-like structure

  • ventral subpallial region: Basal ganglia - formation of “conventional” nuclei

  • ssh: midline of forebrain, controls development

    • knock-out zebra fish - no forebrain, cyclops