Table 2.
Circadian rhythms in DOPAC levels.
| DOPAC- Circadian Rhythms | |||||
|---|---|---|---|---|---|
| Reference_ID | Animals | L/D Cycle | Duration | Brain Region | DOPAC Levels |
| Ferris et al (2014) A [48] | Rats | ZT0–ZT12 | 36h | Caudate Putamen | Higher during DP, lower during LP |
| Paulson et al (1994) [61] | Rats | 6h–20h | 20h | Caudate Nucleus | Higher during DP, lower/stable during LP |
| Paulson et al (1996) [62] | Rats | 6h–20h | 18h20 | Caudate Nucleus | Higher during DP, lower during LP |
| Castaneda et al (2004) A1 [59] | Rats | 20h–8h | 30h | Striatum | Higher during DP, lower during LP |
| Castaneda et al (2004) B1 [59] | Rats | 6h DP–24h LP | 30h | Striatum | Higher during DP, lower during LP |
| Hucke et al (1998) A [51] | Rats, nulliparous | 6h–18h | 8h | Striatum | Higher during DP, stable during LP |
| Hucke et al (1998) B [51] | Rats, primiparous | 6h–18h | 8h | Striatum | Higher during DP, stable during LP |
| Sano et al (1992) A [47] | Rats, young animals | 6h–18h | 24h | Striatum | Higher during DP, lower during LP. Highest values mid DP, lowest values mid LP |
| Sano et al (1992) B [47] | Rats, old animals | 6h–18h | 24h | Striatum | Smaller variation and level of DOPAC than young group |
| Sano et al (1992) C [47] | Rats, isolated | 6h–18h | 24h | Striatum | Stable |
| Sano et al (1992) D [47] | Rats, enriched environment | 6h–18h | 24h | Striatum | Higher levels than isolated, higher during DP, lower during LP |
| Smith et al (1992) [46] | Rats | 7h–19h | 18h | Striatum | Highest during LP, decrease gradually during the entire duration, reach lowest during DP |
| De Marquez-Prado et al (2000) [52] | Rats | 8h–20h | 24h | Neostriatum | Decrease during the entire duration (start at DP) |
| Castaneda et al (2004) A2 [59] | Rats | 20h–8h | 30h | Nucleus Accumbens | Higher during DP, lower during LP |
| Castaneda et al (2004) B2 [59] | Rats | 6h DP–24h LP | 30h | Nucleus Accumbens | Higher during DP, lower during LP. |
| Paulson et al (1994) [61] | Rats | 6h–20h | 20h | Nucleus Accumbens | Increase during LP to be the highest at DP onset. Stay stable during DP, lower during LP |
| Paulson et al (1996) [62] | Rats | 6h–20h | 18h20 | Nucleus Accumbens | Higher during DP, lower during LP |
| Verhagen et al (2009) [64] | Rats | 2h–14h | 36h | Lateral to Nucleus Accumbens Shell | Higher during DP, highest at the end of DP Lowest level mid-LP. High range of fluctuation. |
| Nakayama et al (1993) [56] | Rats | 8h–20h | 24h | Medial Prefrontal Cortex | Peak at DP onset and about 3/4 DP, decrease strongly between the 2 peaks. Decrease during LP |
| Luo et al (2014) [67] | Rats | ? | 24h | SCN | Higher during DP |
Each row represents one study (i.e. an experimental group within a publication) and a qualitative description of the results. Fluctuations are described as “higher” and “lower” disregarding actual magnitudes of changes. Rows are sorted by brain region. Lower case letters indicate separate publications from the same authors in the same year; upper cases letters represent separate groups within publications; numbers represent separate brain regions within animals.
Abbreviations: DOPAC: 3,4-Dihydroxyphenylacetic acid; L/D Cycle: Light-Dark Cycle; LP: Light Phase; DP: Dark Phase; SCN: Suprachiasmatic Nucleus; ZT: Zeitgeber.