Total 125I-α-CtxMII Binding | 125I-α-CtxMII Binding with Cytisine (20 nM) | % Cytisine-Resistant (of total) | |
---|---|---|---|
fmol/mg wet wt. | |||
Telencephalon | |||
Neocortex | |||
Olfactory tubercles | 0.58 ± 0.05 | 0.11 ± 0.03 | 18.9 |
Basal ganglia | |||
Nucleus accumbens, core | 1.44 ± 0.07 | 0.66 ± 0.06 | 45.8 |
Nucleus accumbens, shell | 0.86 ± 0.04 | 0.39 ± 0.03 | 45.3 |
Striatum | 0.81 ± 0.02 | 0.38 ± 0.07 | 46.9 |
Substantia nigra | 0.75 ± 0.19 | 0.39 ± 0.13 | 52.0 |
Ventral tegmental area | 1.29 ± 0.06 | 0.96 ± 0.11 | 74.4 |
Septum | |||
Lambdoid septal zone | 0.82 ± 0.13 | 0.34 ± 0.08 | 41.5 |
Diencephalon | |||
Metathalamus | |||
Dorsolateral geniculate nucleus | 5.00 ± 0.20 | 2.55 ± 0.26 | 51.0 |
Olivary pretectal nucleus | 5.97 ± 0.12 | 3.20 ± 0.39 | 53.6 |
Ventrolateral geniculate nucleus | 5.84 ± 0.18 | 3.31 ± 0.29 | 56.7 |
Epi- and subthalamus | |||
Lateral habenula | 0.83 ± 0.11 | 0.43 ± 0.03 | 51.8 |
Medial habenula | 1.11 ± 0.05 | 0.68 ± 0.07 | 61.3 |
Mesencephalon | |||
Interpeduncular nucleus | 1.38 ± 0.04 | 1.05 ± 0.03 | 76.1 |
Superior colliculus, optic nerve layer | 1.21 ± 0.03 | 0.65 ± 0.03 | 53.7 |
Superior colliculus, superficial grey | 4.13 ± 0.01 | 2.23 ± 0.10 | 54.0 |
Superior colliculus, zonal layer | 5.33 ± 0.10 | 3.47 ± 0.06 | 65.1 |
Pons | |||
Medial vestibular nucleus | 0.50 ± 0.04 | 0.15 ± 0.02 | 30.0 |
Prepositus hypoglossal nucleus | 0.56 ± 0.05 | 0.39 ± 0.06 | 69.6 |
Fiber Tracts | |||
Anterior commissure, anterior | 0.26 ± 0.07 | 0.03 ± 0.03 | 11.5 |
Fasciculus retroflexus | 0.80 ± 0.15 | 0.58 ± 0.07 | 72.5 |
Oculomotor nerve (or root) | 4.71 ± 0.56 | 3.52 ± 0.25 | 74.7 |
Optic tract/brachium superior colliculus | 2.66 ± 0.15 | 1.66 ± 0.19 | 62.4 |
Supraoptic decussation | 2.48 ± 0.04 | 1.44 ± 0.15 | 58.1 |
Mouse brain sections (14 μm) were incubated in the presence of125I-α-CtxMII (0.5 nM) with or without 20 nM cytisine. Binding of 125I-α-CtxMII was detected by exposing βmax film to the sections, followed by digital densitometry of the autoradiographic images. Amounts of ligand bound were calculated by reference to 125I-containing tissue paste standards. Because levels of 125I-α-CtxMII nonspecific binding varied noticeably between brain regions, nonspecific binding was determined in each region, and was used to calculate specific binding (presented in terms of femtomoles of 125I-α-CtxMII bound per milligram of tissue weight). Measurements were made six times in each region, in each mouse, where possible. Values are the mean ± S.E. of binding measured in three different mice.