Table 2.

Quantitative analysis of the density of terminal projections from the Sol and Pa5 after dual anterograde tracing with fluorescently-conjugated cholera toxin beta subunit (CT-B)

Cumulative density score (n = 4)Peak density location (n = 4)
SolPa5SolPa5
Hindbrain
    Medulla
        Caudal ventrolateral (CVL)35.0 ± 2.04 (4)* (p = 1.72 × 10−22)6.00 ± 2.19 (4)−13.6 mm (i)−13.7 mm (i)
        Dorsomedial spinal trigeminal (DMSp5)3.00 ± 1.91 (2)86.25 ± 3.17 (4)* (p = 2.71 × 10−75)−11.2 mm (i)−11.7 mm (i)
        Gigantocellular reticular (DpGi, Gi, LpGi)5.25 ± 5.25 (1)N/Ai
        Inferior olive (IOB, C, D)35.50 ± 6.40 (4)* (p = 6.51 × 10−17)6.50 ± 4.24 (2)−13.0 mm (b)−12.6 mm (b)
        Intermediate reticular (IRt)46.50 ± 3.7 (4)* (p = 0.0005)35.50 ± 3.01 (4)−13.3 mm (i)−13.1 mm (i)
        Lateral reticular (LRt)7.50 ± 6.50 (2)−13.7 mm (i)
        Medullary reticular formation (MdV)3.50 ± 1.80 (4)* (p = 0.04)N/Ai
        Sol79.00 ± 6.15 (4)−13.7 mm (i)
        Paratrigeminal (Pa5)8.00 ± 1.15 (4)−13.9 mm (i)
        Paramedian reticular (PMn)8.25 ± 2.59 (4)* (p = 0.001)−13.5 mm (i)
        Parvicellular recticular (PCRt)18.0 ± 4.08 (4)12.75 ± 4.64 (4)−13.6 mm (i)−13.6 mm (i)
        Pyramids (py)
        Rostral ventrolateral (RVL)40.0 ± 2.61 (4)* (p = 1.55 × 10−17)8.50 ± 2.06 (4)−12.9 mm (i)−12.6 mm (i)
        Spinal trigeminal (Sp5)22.0 ± 8.13 (4)89.50 ± 2.62 (4)* (p = 3.2 × 10−12)−12.6 mm (i)−11.5 mm (i)
        Spinal trigeminal tract (sp5)9.00 ± 3.44 (4)95.00 ± 3.78 (4)* (p = 1.89 × 10−70)−13.7 mm (i)−11.5 mm (i)
    Pons
        Inferior cerebellar peduncle (icp)
        Kölliker–Fuse (KF)14.75 ± 1.89 (4)* (p = 0.003)7.50 ± 0.65 (4)−9.4 mm (i)−9.6 mm (i)
        Locus coeruleus (LC)8.50 ± 1.44 (4)* (p = 0.005)2.00 ± 1.68 (2)−10.7 mm (i)−10.5 mm (i)
        Medial lemniscus (ml)
        Parabrachial
            Medial (MPB)18.00 ± 1.83 (4)43.25 ± 2.14 (4)* (p = 1.15 × 10−8)−9.9 mm (i)−9.9 mm (i)
            Lateral (LPB)40.75 ± 1.38 (4)* (p = 0.0002)25.50 ± 1.55 (4)−9.5 mm (i)−9.9 mm (i)
        Principal sensory trigeminal (Pr5)12.00 ± 10.40 (2)−10.4 mm (i)
        Spinal trigeminal (Sp5)2.75 ± 1.80 (3)64.00 ± 8.69 (4)* (p = 1.6 × 10−10)−12.5 mm (i)−12.5 mm (i)
        Spinal trigeminal tract (sp5)3.00 ± 3.00 (1)44.75 ± 6.60 (4)* (p = 1.1 × 10−8)N/Ai−12.2 mm (i)
        Superior cerebellar peduncle (scp)
        Trapezoid body (Tz)
    Midbrain
        Deep mesencephalic (DpMe)6.75 ± 3.61 (3)4.50 ± 3.34 (2)−7.5 mm (i)−7.6 mm (i)
        Inferior colliculus (CIC, DCIC)25.25 ± 3.47 (4)* (p = 0.003)7.50 ± 6.55 (2)−7.9 mm (c)N/A (c)
        Medial lemniscus (ml)
        Periaqueductual grey (PAG)19.50 ± 3.07 (4)20.00 ± 4.49 (4)N/A (b)N/A (b)
    Sub/hypothalamus and other
        Caudate putamen (CPu)
        Central amygdaloid (CeA)12.25 ± 1.18 (4)* (p = 1.49 × 10−13)N/Ai
        Globus pallidus (GP)
        Lateral hypothalamic area (LH)14.00 ± 1.73 (4)* (p = 2.83 × 10−9)1.25 ± 0.75 (2)−3.6 mm (b)N/A (b)
        Paraventricular hypothalamus (Pa)13.50 ± 1.19 (4)* (p = 2.95 × 10−12)1.00 ± 0.41 (3)N/A (b)N/A (b)
        Subthalmic nucleus (SubT)
        Zona incerta (ZI)47.25 ± 4.01 (4)* (p = 2.57 × 10−19)−4.5 mm (i)
    Thalamus
        Medial lemniscus (ml)
        Mediodorsal thalamus (MD)
        Posterior thalamic group (Po)46.75 ± 1.44 (4)* (p = 6.2 × 10−30)1.25 ± 0.63 (3)−4.2 mm (c)N/A (c)
        Reticular thalamus (Rt)10.00 ± 2.16 (4)* (p = 5.76 × 10−5)−4.0 mm (c)
        Submedius thalamus (Sub)4.00 ± 0.00 (4)* (p = 3.15 × 10−5)−2.7 mm (b)
        Ventral
            Posterior parvicellular thalamus (VPPC)2.00 ± 1.15 (2)−3.8 mm (c)
            Posterolateral thalamus (VPL)55.00 ± 2.52 (4)* (p = 4.46 × 10−33)1.00 ± 1.00 (1)−2.9 mm (c)N/A (c)
            Posteromedial thalamus (VPM)24.50 ± 5.20 (4)* (p = 1.02 × 10−5)−3.7 mm (c)
            Lateral thalamus (VL)
            Medial thalamus (VM)6.00 ± 2.48 (3)* (p = 0.01)N/A (c)
  • CT-B488 and CT-B594 injected into the Sol and Pa5, respectively. All brain regions were assessed in serial sections; data represent the mean cumulative sum of the terminal fiber label density ± SEM (i.e., the sum score across multiple brain sections) and the peak density location (i.e., the brain section with the highest score relative to bregma) for each brain region listed; dashes denote 0 ± 0. Numerical values in parentheses represent the number of animals in the group in which a region contained CT-B-positive fibers.

  • i, Predominantly ipsilateral fiber labeling; b, predominantly bilateral fiber labeling; c, predominantly contralateral fiber labeling; N/A, no peak labeling was evident.

  • *Significant difference between Sol and Pa5 brain regions as determined by a Student's t test.