Identified neurons in the medicinal leech Hirudo verbana

Dorsal aspect

 

Dorsal_Map_Extd

 

Ventral aspect

 

Ventral_Map_Extd

 

 

Identified neurons on the dorsal aspect of segmental ganglia in the leech, Hirudo medicinalis.

 


Map              Major axon         Color            Descriptionb                        Behavioral

numberc          projectionb          codea                                    involvementbc

 


Motoneurons

DE-3         CPNR                green            excitor of DLM                        swimming, LB

                                                                                          crawling

DE-5         CPNR                green                                    swimming, LB

                                                                                          crawling

DE-18       CANR                green                                    swimming

DE-107     CANR                green                                    swimming, LB

VE-4         IPNR                  green            excitor of VLM                        swimming, LB

                                                                                          crawling

VE-8         CPNR                green                                    swimming, LB

VE-108     CANR                green                                    swimming, LB

FE-109      CNR                   green            excitor of lateral                        swimming, LB

                  CNR                                        dorsal-ventral

                                                                  FM

FE-117      CNR                   blue              excitor of medial        

                                                                  dorsoventral FM        

DI-1          CNR                   red                inhibitor of DLM                        swimming, LB

                                                                                          crawling

DI-102      CNR                   red                                        swimming, LB

VI-2          CNR                   red                inhibitor of VLM                        swimming, crawling

VI-7          CNR                   red                                        swimming

VI-119      CNR                   red                                        swimming

FI-101       CNR                   red                inhibitor of                        swimming, LB

                                                                  dorsoventral FM

CE-11       CNR                   blue              excitor of CM                                    

CE-12       CNR                   blue             

CE-112     CNR                   blue             

L (Large LM neuron)           blue              excitor of other                        crawling

                  LM

DE-6         CNR                   blue                                                  local bending

LI-9           CNR                   blue              inhibitor of LM

LE-106     CNR                   blue              excitor of lateral         

                                                                  LM

OE-110     CNR                   blue              excitor of OM             local bending

OE-111     CNR                   blue             

Interneurons

21                                         Green           serotonergic, gating                        swimming

27              AIC                    Red              oscillator                        swimming

                  one ganglion                            240° phase

 

28              AIC,                   red                oscillator                        swimming

                  one ganglion                            120° phase                  

33              AIC,                   red                oscillator                        swimming

                  one ganglion                            240° phase

115            PCC                   red                oscillator                        swimming, LB

                                                                  0° phase

123            PIC                     red                oscillator                        swimming

                  one ganglion                            0° phase                      

125            PIC                     blue              excitor, receives          LB

                                                                  input from P cells

34                                         blue              interacts with

                                                                  T cells, S cells

Mechanosensory cells

P                INR, IC              yellow          mechanosensory                        responds to pressure

N               INR, IC              yellow          mechanosensory                        responds to noxious

Neurosecretory cells

50              IC                       pink              secretary neuron          LB, feeding

 

a.       Color codes correspond to the maps of segmental ganglia (Fig. 2). Coded with green and red are involved in swimming circuits.

 

b.      Abbreviations:

LM-longitudinal muscles     DLM-dorsal LM            VLM-ventral LM

FM-flattener muscles           CM-circular muscles      OM-oblique muscles

NR-nerve root                      CANR-contralateral anterior NR

CNR-contralateral NR         CPNR-contralateral posterior NR

INR-ipsilateral NR               IPNR- ipsilateral posterior NR

IC-ipsilateral connectives     AIC-anterior IC             PIC-posterior IC

PCC-posterior contralateral connectives                     LB-local bending

CM-circular muscle              NR-nerve root                CNR-contralateral NR

INR-ipsilateral NR               CANR-contralateral anterior NR

IC-ipsilateral connectives     AIC-anterior IC             PIC-posterior IC

CC- contralateral connectives                                     PCC-posterior CC

ACC-anterior CC                 Fn-Favre’s nerve.

 

c.       This table provides an update of neurons listed in Muller KJ Nicholls JG Stent GS (1981) Neurobiology of the leech. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.

 

 

 

Identified neurons on the ventral aspect of segmental ganglia in the leech, Hirudo medicinalis.

 


Map              Major axon         Color            Descriptionbb                        Behavioral

numberc        projectionb          codea                                    involvementbc

 


Motoneurons

AE            CNR                   blue              annuli erector              change skin surface

                                                                                                      from smooth to ridged

                                                                                                            input from T cell

CV            CNR                   blue              excitor of                        crawling

                                                                  ventrolateral

                                                                        CM

HE            INR                    blue              cardiac rhythmic         control HN

                        (M3-19)                                   movement

AP             CNR                   blue              input from P cell                        position detection,

                                                                                                crawling

152            CNR                   blue              CM excitor                        crawling

166            CNR                   blue              CM inhibitor                        crawling

Interneurons

61              IC (2 ganglia)     green            serotonergic                        swimming

                                                                  gating                         

204            Fn (unpaired)     green            gating                        swimming, crawling,

                                                                                          behavioral decision

205            Fn (unpaired)     green            gating,                        swimming

                  found in M9

208            IC (unpair)         green            oscillator                        swimming

60              IC (2 ganglia)     red                oscillation 240°                        swimming

151            IC (NR)              blue              non-spiking                 a negative feedback

                                                                                                            to limit excessive

                                                                                                      motor activity,

                                                                                          crawling

153            CANR                blue              receive excitatory        photo reception,

                                                                  photosensory input                         swimming          

                                                                  oscillation 180°

154                                       blue              photo-sensory input                        photoreception

157            CC                      blue              EPSP long latency      LB

159            PIC                     blue              EPSP long latency      LB, crawling

160                                       blue              shifts swim phase                        swimming?

                                                                  but no oscillation

161            IC                       blue              EPSP from P cell        LB

162            IC                       blue              EPSP from P cell        LB

169            CC                      blue              EPSP long latency                        swimming, LB

201            CC                      blue              receive inhibition         water motion

                                                                  from the SMRs                           detection

202            CC                      blue              receive excitation        water motion

                                                                  from the SMRs                        detection

213            AIC                    blue              ascending                         crawling

215                                       blue              receive excitation            photosensory

                                                                  (ipsi-) sensillum 7            reception

216                                       blue              receive photo               photosensory

                                                                  sensory inputs               reception

212            ACC                   blue              EPSP from P cell        LB

218            IC                       blue              Spontaneous EPSP     LB

258            INR                    blue              with large soma                        crawling

S                Fn                       blue                                                  LB, shortening,

                                                                                          Learning, crawling

HN            IC                       blue              Inhibitor IN                 control of heartbeat

                  (M1-M7)                                 Heart oscillator

E21           Fn                       M21              Trigger/gating                        swimming

Mechanosensory cell

T               IC (NR)              yellow          responds to tactile       touch

                  (T1, T2, T3)                               stimuli                        

P                IC (NR)              yellow          respond to pressing                        pressure

                  (P1, P2)                                     stimuli on skin

N               IC (NR)              yellow          respond to noxious                        nociception

                  (N1, N2)                                   stimuli on skin, gut

 

Neurosecretory cell

R               ICNR, IC           pink              contains serotonin                        swimming, feeding

(Retzius)                                                                                        muscle relaxation

50 (Leydig)                          pink                                                                          LB, feeding

 

 


aColor codes correspond to the maps of segmental ganglia (Fig. 2). Coded with green and red are involved in swimming circuits.

 

bAbbreviations

LM-longitudinal muscles     DLM-dorsal LM            VLM-ventral LM

FM-flattener muscles           CM-circular muscles      OM-oblique muscles

NR-nerve root                      CANR-contralateral anterior NR

CNR-contralateral NR         CPNR-contralateral posterior NR

INR-ipsilateral NR               IPNR- ipsilateral posterior NR

IC-ipsilateral connectives     AIC-anterior IC             PIC-posterior IC

PCC-posterior contralateral connectives                     LB-local bending

CM-circular muscle              NR-nerve root                CNR-contralateral NR

INR-ipsilateral NR               CANR-contralateral anterior NR

IC-ipsilateral connectives     AIC-anterior IC             PIC-posterior IC

CC- contralateral connectives                                     PCC-posterior CC

ACC-anterior CC                 Fn-Favre’s nerve.

 

cThis table provides an update of neurons listed in Muller KJ Nicholls JG Stent GS (1981) Neurobiology of the leech. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory, Appendix Table 1

 

References for additions to appendix Table 1

 

Cell DE-18  Nusbaum MP (1986) Synaptic basis of swim initiation in the leech. III. Synaptic effects of serotonin-containing interneurones (cells 21 and 61) on swim CPG neurones (cells 18 and 208). J Exp Biol 122:303-321

 

Cell 115  Friesen WO (1989) Neuronal control of leech swimming movements. II. Motor neruon feedback to oscillator cells 115 and 28. J Comp Physiol A 166:205-215

 

Cells CV, 152, 166, AP, 159, 213, 258  Baader AP (1997) Interneuronal and motor patterns during crawling behavior of semi-intact leeches. J Exp Biol 200:1369-1381

 

Leydig cell  Wilson RJ, Kristan WB Jr, Kleinhaus AL (1996) An increase in activity of serotonergic Retzius neurones may not be necessary for the consummatory phase of feeding in the leech Hirudo medicinalis. J Exp Biol 199:1405-1414

LB behavior Lockery SR, Kristan WB Jr. (1990) Distributed processing of sensory information in the leech. II. Identification of interneurons contributing to the local bending reflex. J Neurosci 10:1816-29

Garcia-Perez E, Zoccolan D, Pinato G, Torre V (2004) Dynamics and reproducibility of a moderately complex sensory-motor response in the medicinal leech. J Neurophysiol 92:1783-1795

Wittenberg G, Kristan WB Jr (1992) Analysis and modeling of the multisegmental coordination of shortening behavior in the medicinal leech. II. Role of identified interneurons. J Neurophysiol 68:1693-1707

 

AP cell  Shan D, Zhang RJ (2001) Frequency coding of positional information by an identified neuron, the AP cell, in the leech, Whitmania pigra. Brain Res Bull 56:511-515

AE cell  Rodriguez MJ, Iscla IR, Szczupak L (2004) Modulation of mechanosensory responses by motoneurons that regulate skin surface topology in the leech. J Neurophysiol 91:2366-2375

Cell 151 Wadepuhl M (1987) A morpho- and physiologically uncommon neuron in the leech CNS. Naturwissenschaften 74:43-45

 

 

                                                                        
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