Journal: The Journal of Comparative Neurology

Article Title: Multiple Longitudinal Tracts in the Cephalopod Arm Sensorimotor System

doi: 10.1002/cne.70165

Figure Lengend Snippet: Longitudinal tracts in the aboral neuropil. (a, b) The aboral neuropil (NP) is dominated by longitudinal fibers. (a) Longitudinal section of an injection of dextran (cyan) into the aboral NP demonstrating longitudinal fibers. Key displays plane of section. Oval on key denotes injection site. (b) Maximum projection of a longitudinal wholemount with SMI‐31 immunostaining (cyan) marks the longitudinal fibers in the aboral NP. The oral fascicles (denoted by *) that become the oral roots targeting the sucker are also readily visible in this preparation. (c) Horizontal section at the transition from the oral NP to the aboral NP stained for SMI‐31 (cyan), F‐actin (magenta), and DAPI (gray). There are two prominent bilateral longitudinal tracts (bLT), marked by white arrowheads. (d) Maximum projection of a horizontal wholemount stained for SMI‐31 (cyan) confirms that the bLT corresponds to the most aboral branch point of the oral fascicles. (e–f) Summary diagrams showcasing the longitudinal tracts (blue) in the aboral NP in a longitudinal ANC cartoon (e) and a horizontal ANC cartoon (f). The bLT are denoted by thicker lines, and, in (e), are offset to demonstrate the tract on the opposite side. * in (e) denote ANC enlargements for suckers on the same side, + denote ANC enlargements for suckers on the opposite side. Scale bars: 100 µm. aNP, aboral neuropil; bLT, bilateral longitudinal tract; CBL, cell body layer; CBT, cerebrobrachial tract; NP, neuropil; oNP, oral neuropil.

Article Snippet: Clone SMI‐31 reacts with a phosphorylated epitope of neurofilament in mammals and neurofilament 220 in squid (Sternberger and Sternberger ; Grant et al. ; Grant and Pant ), and it has been employed successfully in octopus arm tissue (Olson, Schulz, et al. ).

Techniques: Injection, Immunostaining, Staining

Journal: The Journal of Comparative Neurology

Article Title: Multiple Longitudinal Tracts in the Cephalopod Arm Sensorimotor System

doi: 10.1002/cne.70165

Figure Lengend Snippet: Longitudinal tracts in the oral neuropil. (a) Schematic of a longitudinal axial nerve cord (ANC) demonstrating the trajectories of the internal longitudinal tract (iLT, green) and the oral longitudinal tract (oLT, red) as the tracts travel from sucker to sucker. * denotes ANC enlargements for suckers on the same side. + denotes ANC enlargement for suckers on the opposite side. (b) Diagram of a horizontal section of the ANC demonstrating the paths of the oLT (red) and iLT (green) in the oral portion of the ANC. (c) Maximum projection of a transverse ANC wholemount stained for SMI‐31 (cyan). The iLT is outlined with a yellow dashed line as it crosses the midline. Key indicates transverse plane of section. Scale bar: 100 µm. (d) Horizontal section through the oral NP stained for SMI‐31 (cyan), F‐actin (magenta), and DAPI (gray). The iLT, marked by yellow arrowheads, follows the internal side of the ANC. (e) Maximum projection of a transverse ANC wholemount stained for SMI‐31 (cyan). The oLT is outlined with a white dashed line. Key indicates transverse plane of section. Scale bar: 100 µm. (f) Horizontal section through the oral NP stained for SMI‐31 (cyan), F‐actin (magenta), and DAPI (gray). The oLT, marked by white arrowheads, is positioned close to the midline, located oral to the iLT, and oscillates through ANC enlargements. Keys indicate horizontal plane of section. Scale bar: 150 µm. (g, h) The oLT bifurcates at the transition between sucker enlargements. White arrowheads mark the oral branch of the oLT, and white arrows mark the aboral branch of the oLT. See loop of the oLT in (a). (g) Injection of dextran labeling the oLT at the transition between sucker enlargements. Keys indicate plane of section and field of view. Ovals on keys indicate injection site. (h) Maximum projection of a transverse ANC wholemount stained for SMI‐31 (cyan) at the transition between sucker enlargements. The iLT is outlined with a yellow dashed line. The aboral oLT trunk loops over the iLT. The aboral and oral oLT branches connect to the oLT on the other side. Scale bars: 100 µm. ANC, axial nerve cord; ExA, external side of the axial nerve cord; InA, internal side of the axial nerve cord; iLT, internal longitudinal tract; NP, neuropil; oLT, oral longitudinal tract.

Article Snippet: Clone SMI‐31 reacts with a phosphorylated epitope of neurofilament in mammals and neurofilament 220 in squid (Sternberger and Sternberger ; Grant et al. ; Grant and Pant ), and it has been employed successfully in octopus arm tissue (Olson, Schulz, et al. ).

Techniques: Staining, Injection, Labeling

Journal: The Journal of Comparative Neurology

Article Title: Multiple Longitudinal Tracts in the Cephalopod Arm Sensorimotor System

doi: 10.1002/cne.70165

Figure Lengend Snippet: Organization of the E. berryi tentacle club nervous system. (a) Transverse section of the E. berryi tentacle club stained for acetylated α‐tubulin (acTUBA; cyan) and F‐actin (magenta). The main components of the nervous system are highlighted. The tentacle club is lined with minute suckers at the end of long tube‐like stalks. Scale bar: 500 µm. (b) Transverse section of the axial nerve cord (ANC) in the E. berryi tentacle club stained for acTUBA (cyan) and F‐actin (magenta). The neuropil (NP) is expanded and the aboral longitudinal tract (aLT) appears compressed. (c) Transverse section of the ANC stained for SMI‐31 (cyan), F‐actin (magenta), and DAPI (gray). The aLT and the oral longitudinal tract (oLT) are composed of small fibers, and the oLT is within the NP. Scale bars: 250 µm. (d, e) The ANC issues nerves that travel down the long tube‐like sucker stalks to target the minute suckers. (d) Longitudinal section through the tentacle club stained for SMI‐31 (cyan) and F‐actin (magenta). White arrowheads point to ANC nerves as they begin to travel along the sucker stalks. (e) Longitudinal section through the tentacle club stained for SMI‐31 (cyan) and F‐actin (magenta). White arrows indicate an ANC nerve traveling along the sucker stalk to target the sucker. Scale bars: 25 µm. acTUBA, acetylated α‐tubulin; aLT, aboral longitudinal tract; ANC, axial nerve cord; CBL, cell body layer; IMNC, intramuscular nerve cord; k, swimming keel; NP, neuropil; oLT, oral longitudinal tract.

Article Snippet: Clone SMI‐31 reacts with a phosphorylated epitope of neurofilament in mammals and neurofilament 220 in squid (Sternberger and Sternberger ; Grant et al. ; Grant and Pant ), and it has been employed successfully in octopus arm tissue (Olson, Schulz, et al. ).

Techniques: Staining

Journal: The Journal of Comparative Neurology

Article Title: Multiple Longitudinal Tracts in the Cephalopod Arm Sensorimotor System

doi: 10.1002/cne.70165

Figure Lengend Snippet: Organization of D. Pealeii arm and tentacle nervous system. (a–c) Transverse section of the D. pealeii arm (a), tentacle stalk (b) and tentacle club (c) stained for acTUBA (cyan) and F‐actin (magenta). The main components of the nervous system are highlighted. Scale bars: 500 µm. (d–f) Transverse section of the axial nerve cord in the D. pealeii arm (d), tentacle stalk (e) and tentacle club (f) stained for acTUBA (cyan) and F‐actin (magenta). Each ANC has an aboral longitudinal tract (aLT) and an oral longitudinal tract (oLT). + denotes brachial artery. Scale bars: 250 µm. (h–k) The aLT and oLT are composed of large fibers. (h, i) Transverse sections through the aLT (h) and oLT (i) in arm ANC stained for SMI‐31 (cyan) and F‐actin (magenta). (j, k) Transverse sections through the aLT (j) and oLT (k) in the tentacle stalk ANC stained for SMI‐31 (cyan) and F‐actin (magenta). Scale bars: 50 µm. (l–n) Horizontal sections through oLT in the arm (l), tentacle stalk (m) and tentacle club (n) stained for SMI‐31 (cyan) and F‐actin (magenta). In the arm (l) and tentacle club (n), where there are suckers, the oLT conspicuously weaves around neuropil (NP). Scale bars: 100 µm. acTUBA, acetylated α‐tubulin; aLT, aboral longitudinal tract; ANC, axial nerve cord; CBL, cell body layer; IMNC, intramuscular nerve cord; NP, neuropil; oLT, oral longitudinal tract.

Article Snippet: Clone SMI‐31 reacts with a phosphorylated epitope of neurofilament in mammals and neurofilament 220 in squid (Sternberger and Sternberger ; Grant et al. ; Grant and Pant ), and it has been employed successfully in octopus arm tissue (Olson, Schulz, et al. ).

Techniques: Staining

Journal: The Journal of Comparative Neurology

Article Title: Multiple Longitudinal Tracts in the Cephalopod Arm Sensorimotor System

doi: 10.1002/cne.70165

Figure Lengend Snippet: Longitudinal tracts in D. pealeii neuropil. (a) Transverse section through the axial nerve cord (ANC) in the squid arm stained for acetylated α‐tubulin (acTUBA, cyan) and F‐actin (magenta). Clear longitudinal tracts (LT), marked with white dashed line, are apparent by a decrease in acTUBA labeling. Inset depicts field of view. Scale bar: 100 µm. (b) Transverse section through the D. pealeii arm ANC with SMI‐31(cyan) immunostaining labels the fibers in the longitudinal tracts. Scale bar: 50 µm. (c) Horizontal section through the D. pealeii arm ANC stained for acTUBA. The longitudinal tracts are located at the border of the cell body layer (CBL) and neuropil (NP). Scale bar: 50 µm. (d) Transverse section through the ANC in the tentacle stalk stained for acetylated α‐tubulin (acTUBA, cyan) and F‐actin (magenta). There are no defined NP tracts. Scale bar: 100 µm. (e, f) Longitudinal sections through the tentacle stalk ANC stained for SMI‐31 (cyan) and F‐actin (magenta). Longitudinal fibers are abundant at the interface of the CBL and NP (e) but somewhat reduce in the center (f). Insets display plane of section. Scale bars: 100 µm. acTUBA, acetylated α‐tubulin; aLT, aboral longitudinal tract; ANC, axial nerve cord; CBL, cell body layer; LT, longitudinal tract; NP, neuropil; oLT, oral longitudinal tract.

Article Snippet: Clone SMI‐31 reacts with a phosphorylated epitope of neurofilament in mammals and neurofilament 220 in squid (Sternberger and Sternberger ; Grant et al. ; Grant and Pant ), and it has been employed successfully in octopus arm tissue (Olson, Schulz, et al. ).

Techniques: Staining, Labeling, Immunostaining

Journal: The Journal of Comparative Neurology

Article Title: Multiple Longitudinal Tracts in the Cephalopod Arm Sensorimotor System

doi: 10.1002/cne.70165

Figure Lengend Snippet: Organization of E. berryi arm and tentacle stalk nervous system. (a, b) Transverse section of the E. berryi arm (a) and tentacle stalk (b) stained for acTUBA (cyan) and F‐actin (magenta). The main components of the nervous system are highlighted. Scale bars: 500 µm. (c, d) Transverse section of the axial nerve cord (ANC) in the E. berryi arm (c) and tentacle stalk (d) stained for acTUBA (cyan) and F‐actin (magenta). Each ANC has an aboral longitudinal tract (aLT) and an oral longitudinal tract (oLT). Scale bars: 250 µm. (e, f) The aLT and oLT in the E. berryi arm are composed of small fibers. Transverse sections through the aLT (e) and oLT (f) in arm ANC stained for SMI‐31 (cyan), F‐actin (magenta), and DAPI (gray). Notably, the arm oLT is encompassed by the cell body layer of the ANC. Scale bars: 50 µm. (g) Horizontal section through the oLT in the arm ANC stained for SMI‐31 (cyan) and F‐actin (magenta). The oLT runs straight through sucker enlargements, denoted by *. Scale bar: 100 µm. (h, i) The aLT and oLT in the tentacle stalk are composed of large fibers. Transverse section through the aLT (h) and the oLT (i) in the tentacle stalk ANC immunostained for SMI‐31 (cyan), F‐actin (magenta), and DAPI (gray). The oLT in the tentacle stalk is not within the cell body layer. Scale bars: 50 µm. (j) Horizontal section through the oLT in the tentacle stalk ANC stained for SMI‐31 (cyan) and F‐actin (magenta). The oLT runs straight. Scale bar: 100 µm. (k–m) Longitudinal fibers in the NP of the arm and tentacle stalk ANC are abundant at the interface of the CBL and the NP. (k) Horizontal section through the arm ANC stained for SMI‐31 (cyan). The longitudinal fibers (LF) are located at the border of the cell body layer and neuropil. Key displays plane of section. Scale bar: 50 µm. (l, m) Longitudinal sections through the tentacle stalk ANC immunostained for SMI‐31 (cyan) and F‐actin (magenta). Longitudinal fibers are abundant at the interface of the CBL and NP (l) but reduce in the center (m). Key displays plane of section. Scale bars: 100 µm. acTUBA, acetylated α‐tubulin; aLT, aboral longitudinal tract; ANC, axial nerve cord; CBL, cell body layer; IMNC, intramuscular nerve cord; LF, longitudinal fibers; NP, neuropil; oLT, oral longitudinal tract.

Article Snippet: Clone SMI‐31 reacts with a phosphorylated epitope of neurofilament in mammals and neurofilament 220 in squid (Sternberger and Sternberger ; Grant et al. ; Grant and Pant ), and it has been employed successfully in octopus arm tissue (Olson, Schulz, et al. ).

Techniques: Staining